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1 operating system
Operating systems are the most important system software. Operating system is a set of programs that control and supervises the hardware of a computer and provides services to application software, programmers and users of computer.Without operating system a computer cannot do anything useful. A user cannot communicate directly with the computer hardware, so the operating system acts as an intermediary between user of a computer and the computer hardware. The primary goal of an operating system is to make the computer convenient to use. The secondary goal is to use the computer efficiently.
Some important tasks of an operating system are managing the resources of the computer such as Central Processing Unit (CPU), memory, disk drives and printer and running user programs. Every type of computer has its own operating system. Operating system for mainframe and other large computers are very complex since they must keep track of several programs from several users all running in the same time frame.
Following are some of the popular operating systems used in personal computers: DOS, Windows, Unix, Linus, Solaris, etc.
2 Wireless system
Wireless communication system engineers want to “speak a little RF” in order to bridge the gap between themselves – who prefer to think in terms of bit error rate and related characteristics such as Eb/No, delay spread, and intersymbol interference -- and their colleagues, the RF engineers -- who prefer to think in terms of network parameters, noise figure, and IP3.
Of course fundamentally the concepts are closely related -- RF impairments and their affect on system performance -- but how to get these two groups on the same page?
MathWorks customers have had great success in opening up this dialog using a method we call Model-Based Design: System engineers create an executable specification in the form of a Simulink® model that can be used to determine RF specifications. RF engineers use their third-party RF circuit transistor-level tools (e.g., harmonic balance) to build an RF circuit that meets the spec. Once they have a candidate solution, they can extract a verification model and give it back to the system engineers. They import this into the Simulink model and verify the overall performance of the system with the impairments from the candidate RF circuit included.
The two engineering teams can go back and forth, iterating to find an optimal solution as the design effort proceeds. Perhaps the RF section can use a more efficient or less costly circuit if the signal processing algorithms are improved a bit. Or perhaps a small increase in fixed-point word length can free up some of the implementation loss budget to enable a lower cost or lower current RF component to be used. These opportunities for design optimization are enabled by allowing the two groups of engineers to speak the other’s language.
3 Essay on General Definition of Communication
Communication is a process. Webster's Dictionary defines a process as a "continuous...series of changes taking place in a definite manner" (Webster's, 1997, p. 530). So is communication comprised of a series of changes or events that collectively capture the true meaning of the message we want to convey. It truly is a wonder that we are able to get our message across at all sometimes, given all of the opportunities for miscommunication that abound in the course of exchange of information.
The process of communication on its face appears to be simple, but it is actually quite complicated. Adler and Elmhorst state that the process begins with "a sender [or encoder], the person who transmits a message" (p. 5). The sender's message is intended to elicit a response from a receiver, or the person who is supposed to receive the message. However, messages can convey information that is both deliberate and unintentional; for example, a manager may be abrupt while giving a subordinate feedback because he is late for a meeting, and consequently the manager's feedback is construed as negative. Thus, it is incumbent upon the sender to develop a sense of awareness with regard to what is said and how it is presented. The sender has a responsibility to "choose certain words or nonverbal methods to send an intentional message" because "the words...a communicator chooses to deliver a message can make a tremendous difference in how that message is received" (p. 6). The person receiving the message (the decoder) attaches meaning not only to the words that the message conveys, but also to the nonverbal cues that may or may not be intentional; as a result, "there is no guarantee that [the message] will be understood as the sender intended it to be" (p. 6). The decoder's response, or feedback, to the sender is based on the decoder's interpretation of the sender's message, whether deliberate, unintentional or otherwise.
4Radio Wave Propagation
he Sun’s electromagnetic radiation
is a continuum that spans radio
wavelengths through the infrared,
visible, ultraviolet, x-ray, and beyond. Ultraviolet radiation, through a process
termed photo ionization, interacts with upper
atmospheric constituents to form an ionized
layer called the ionosphere.
The ionosphere affects radio signals in different
ways depending on their frequencies (see Figure 1), which range from extremely low (ELF)
to extremely high (EHF). On frequencies below about 30 MHz the ionosphere may act as an
efficient reflector, allowing radio communication to distances of many thousands of kilometers. Radio signals on frequencies above 30
MHz usually penetrate the ionosphere and,
therefore, are useful for ground-to-space communications.
The ionosphere occasionally becomes disturbed as it reacts to certain types of solar activity. Solar flares are an example; these disturbances can affect radio communication in all
latitudes. Frequencies between 2 MHz and
30 MHz are adversely affected by increased
absorption, whereas on higher frequencies
(e.g., 30–100 MHz) unexpected radio reflections can result in radio interference.
Scattering of radio power by ionospheric irregularities produces fluctuating signals (scintillation), and propagation may take unexpected
paths. TV and FM (on VHF) radio stations are
affected little by solar activity, whereas HF
ground-to-air, ship-to-shore, Voice of America, Radio Free Europe, and amateur radio are
affected frequently. Figure 2 illustrates various
ionospheric radio wave propagation effects.Some satellite systems, which employ linear polarization on frequencies up to 1 GHz, are affected by Faraday rotation of the plane of polarization.
5 web browser
A web browser is a software application for retrieving, presenting and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier (URI) and may be a web page, image, video or other piece of content.[1] Hyperlinks present in resources enable users easily to navigate their browsers to related resources. A web browser can also be defined as an application software or program designed to enable users to access, retrieve and view documents and other resources on the Internet.
Although browsers are primarily intended to use the World Wide Web, they can also be used to access information provided by web servers in private networks or files in file systems. The major web browsers are Chrome, Firefox, Internet Explorer, Opera, and Safari.
The first web browser was invented in 1990 by Sir Tim Berners-Lee. It was called WorldWideWeb (no spaces) and was later renamed Nexus.[3]
In 1993, browser software was further innovated by Marc Andreessen with the release of Mosaic (later Netscape), "the world's first popular browser",[4] which made the World Wide Web system easy to use and more accessible to the average person. Andreesen's browser sparked the internet boom of the 1990s.[4] The introduction of Mosaic in 1993 – one of the first graphical web browsers – led to an explosion in web use. Andreessen, the leader of the Mosaic team at NCSA, soon started his own company, named Netscape, and released the Mosaic-influenced Netscape Navigator in 1994, which quickly became the world's most popular browser, accounting for 90% of all web use at its peak (see usage share of web browsers).
Microsoft responded with its Internet Explorer in 1995, also heavily influenced by Mosaic, initiating the industry's first browser war. Bundled with Windows, Internet Explorer gained dominance in the web browser market; Internet Explorer usage share peaked at over 95% by 2002.[5]
6 Definitions of Communication
1. ” Communication is transfer of information from one person to another,whether or not it elicits confidence. But the information transferred must be understandable to the receiver – G.G. Brown.
2. “Communication is the intercourse by words, letters or messages”- Fred G. Meyer.
We can now proceed to define communication from what we have seen above. To define means to give the precise and exact meaning of a word. The exact meaning of the word communicate is ‘to share’ or ‘to participate’. The dictionaries say that communication is the transmission of a message or information by speaking or writing. Another dictionary declares that communication is giving or exchanging information, signals, messages by talk or gestures or writing. Yet another definition says that communication is social intercourse. Communication is all this and much more. A good definition should not only give the precise meaning but also throw light on the scope of the word / expression.
Communication is giving, receiving or exchanging ideas, information, signals or messages through appropriate media, enabling individuals or groups to persuade, to seek information, to give information or to express emotions.
This broad definition includes body-language, skills of speaking and writing. It outlines the objectives of communication. It emphasizes listening as an important aspect of communication.
7 Receiver (radio)
How radio communication works. Information such as sound is transformed into an electronic signal which is applied to a transmitter. The transmitter sends the information through space on a radio wave (electromagnetic wave). A receiver intercepts some of the radio wave and extracts the information-bearing electronic signal, which is converted back to its original form by a transducer such as a speaker.
In radio communications, a radio receiver is an electronic device that receives radio waves and converts the information carried by them to a usable form. It is used with an antenna. The antenna intercepts radio waves (electromagnetic waves) and converts them to tiny alternating currents which are applied to the receiver, and the receiver extracts the desired information. The receiver uses electronic filters to separate the desired radio frequency signal from all the other signals picked up by the antenna, an electronic amplifier to increase the power of the signal for further processing, and finally recovers the desired information through demodulation.
The information produced by the receiver may be in the form of sound (an audio signal), images (a video signal) or data (a digital signal).[1] A radio receiver may be a separate piece of electronic equipment, or an electronic circuit within another device. Devices that contain radio receivers include television sets, radar equipment, two-way radios, cell phones, wireless computer networks, GPS navigation devices, satellite dishes, radio telescopes, bluetooth enabled devices, garage door openers, and baby monitors.
Early broadcast radio receiver. Truetone model from about 1940
In consumer electronics, the terms radio and radio receiver are often used specifically for receivers designed to reproduce the audio (sound) signals transmitted by radio broadcasting stations – historically the first mass-market commercial radio application.
8 electric circuit
electric circuit, unbroken path along which an electric current exists or is intended or able to flow. A simple circuit might consist of an electric cell (the power source), two conducting wires (one end of each being attached to each terminal of the cell), and a small lamp (the load) to which the free ends of the wires leading from the cell are attached. When the connections are made properly, current flows, the circuit is said to be "closed," and the lamp will light. The current flows from the cell along one wire to the lamp, through the lamp, and along the other wire back to the cell. When the wires are disconnected, the circuit is said to be "open" or "broken." In practice, circuits are opened by such devices as switches, fuses, and circuit breakers (see fuse, electric; circuit breaker; short circuit). Two general circuit classifications are series and parallel. The elements of a series circuit are connected end to end; the same current flows through its parts one after another. The elements of a parallel circuit are connected so that each component has the same voltage across its terminals; the current flow is divided among its parts. When two circuit elements are connected in series, their effective resistance (impedance if the circuit is being fed alternating current) is equal to the sum of the separate resistances; the current is the same in each component throughout the circuit. When circuit elements are connected in parallel, the total resistance is less than that of the element having the least resistance, and the total current is equal to the sum of the currents in the individual branches. A battery-powered circuit is an example of a direct-current circuit; the voltages and currents are constant in magnitude and do not vary with time. In alternating-current circuits, the voltage and current periodically reverse direction with time. A standard electrical outlet supplies alternating current. Lighting circuits and electrical machinery use alternating current circuits. Many other devices, including computers, stereo systems, and television sets, must first convert the alternating current to direct current. That is done by a special internal circuit usually called a power supply.
9 central processing
A central processing unit (CPU), also referred to as a central processor unit,[1] is the hardware within a computer that carries out the instructions of a computer program by performing the basic arithmetical, logical, and input/output operations of the system. The term has been in use in the computer industry at least since the early 1960s.[2] The form, design, and implementation of CPUs have changed over the course of their history, but their fundamental operation remains much the same.
A computer can have more than one CPU; this is called multiprocessing. Some integrated circuits (ICs) can contain multiple CPUs on a single chip; those ICs are called multi-core processors.
Two typical components of a CPU are the arithmetic logic unit (ALU), which performs arithmetic and logical operations, and the control unit (CU), which extracts instructions from memory and decodes and executes them, calling on the ALU when necessary.
Not all computational systems rely on a central processing unit. An array processor or vector processor has multiple parallel computing elements, with no one unit considered the "center". In the distributed computing model, problems are solved by a distributed interconnected set of processors.
The term is sometimes used incorrectly by people who are not computer specialists to refer to the cased main part of a desktop computer containing the motherboard, processor, disk drives, etc., i.e., not the display monitor or keyboard.
10 Computer
Definition of Computer : Computer is an electronic device that is designed to work with Information.The term computer is derived from the Latin term ‘computare’, this means to calculate.Computer can not do anything without a Program.it represents the decimal numbers through a string of binary digits. The Word 'Computer'usually refers to the Center Processor Unit plus Internal memory.
Computer is an advanced electronic device that takes raw data as input from the user and processes these data under the control of set of instructions (called program) and gives the result (output) and saves output for the future use. It can process both numerical and non-numerical (arithmetic and logical) calculations.The basic components of a modern digital computer are: Input Device,Output Device,Central Processor. A Typical modern computer uses LSI Chips.
Charles Babbage is called the "Grand Father" of the computer.The First mechanical computer designed by charles Babbage was called Analytical Engine. It uses read-only memory in the form of punch cards.
11 Hardware
Hardware has so many categories. The most popular is CPU or Central Processing Unit which well known as Processor. CPU is the core available in computer, Notebook and other devices. It has the power to control any other devices. The use of it require a software to receive input and send the command to other components. Other category of Hardware would be Motherboard or Mainboard. It is the essential part as the place for processor, memory (RAM) and other peripherals. Mainboard play an important role as it is the host of other components. It connect Processor with the memories and HardDisk or other components. Memory is another category which always available in any electronic devices. It is used to bridge the processor with other components. It also able to save the data temporary. Graphic Processing Unit or GPU is well known as VGA or Video Graphic Adapter. It focus on displaying the result of computing to the monitor.
Hardware is really important as it make the devices ‘alive’. There are so much categories available in hardware. basically hardware is the backbone of computer, Phones and any electronic gadgets. Hardware is controlled by Software. To make any hardware work as expected, People created software to connect people with the hardware. Software will function as ‘The communication’ between hardware and the people.
12 Windows XP
The next major version of Windows, Windows XP, was released on October 25, 2001. The introduction of Windows XP aimed to unify the consumer-oriented Windows 9x series with the architecture introduced by Windows NT, a change which Microsoft promised would provide better performance over its DOS-based predecessors. Windows XP would also introduce an redesigned user interface (including an updated Start menu and a "task-oriented" Windows Explorer), streamlined multimedia and networking features, Internet Explorer 6, integration with Microsoft's .NET Passport services, modes to help provide compatibility with software designed for previous versions of Windows, and Remote Assistance functionality.[18]
At retail, Windows XP was now marketed in two main "editions": the "Home" edition was targeted towards consumers, while the "Professional" edition was targeted towards business environments and power users, and included additional security and networking features. Home and Professional were later accompanied by the "Media Center" edition (designed for home theater PCs, with an emphasis on support for DVD playback, TV tuner cards, DVR functionality, and remote controls), and the "Tablet PC" edition (designed for mobile devices meeting its specifications for a tablet computer, withsupport for stylus pen input and additional pen-enabled applications).[19][20][21] Mainstream support for Windows XP ended on April 14, 2009. Extended support will continue until April 8, 2014.[22]
After Windows 2000, Microsoft also changed its release schedules for server operating systems; the server counterpart of Windows XP, Windows Server 2003, was released in April 2003.[17] It was followed in December 2005 by Windows Server 2003 R2.
13 types of software
Software components of a computer system have no physical presence, they are stored in digital form within computer memory. There are different categories of software, including system software, utilities and applications software. Software can also be described as being either generic or bespoke.
System software is the software used to manage and control the hardware components and which allow interaction between the hardware and the other types of software. The most obvious type of system software is the computer's operating system but device drivers are also included within this category.
Utility software is software such as anti-virus software, firewalls, disk defragmenters and so on which helps to maintain and protect the computer system but does not directly interface with the hardware.
Applications software (also known as 'apps') are designed to allow the user of the system complete a specific task or set of tasks. They include programs such as web browsers, office software, games and so on. They are usually the reason you bought the computer system in the first place and aren't concerned with the management or maintenance of the system itself.
Any individual software package, whichever of the above types it falls into, can be either generic (or 'off-the-shelf') or it can be bespoke (custom-built). Generic software is mass produced with the intention that it will be used by a wide variety of different users in a range of different situations. Bespoke software is created for a specific purpose which will be used in a known environment.
Often generic software is used when there is a package available that meets the needs of the user. Because it is used by many more people the cost of creating it is spread over a greater number of people or organisations and so the cost to the individual is much lower. It also has the advantage that it is available immediately there's no waiting time involved while the software package is designed, created and tested. Bespoke software has the advantage that it can be tailor made to exact specifications but it significantly more expensive and will take time to create.
14 Operating system
Early computers were built to perform a series of single tasks, like a calculator. Basic operating system features were developed in the 1950s, such as resident monitor functions that could automatically run different programs in succession to speed up processing. Operating systems did not exist in their modern and more complex forms until the early 1960s.[4] Hardware features were added that enabled use of runtime libraries, interrupts, and parallel processing. When personal computers became popular in the 1980s, operating systems were made for them similar in concept to those used on larger computers.
In the 1940s, the earliest electronic digital systems had no operating systems. Electronic systems of this time were programmed on rows of mechanical switches or by jumper wires on plug boards. These were special-purpose systems that, for example, generated ballistics tables for the military or controlled the printing of payroll checks from data on punched paper cards. After programmable general purpose computers were invented, machine languages (consisting of strings of the binary digits 0 and 1 on punched paper tape) were introduced that sped up the programming process (Stern, 1981).
In the early 1950s, a computer could execute only one program at a time. Each user had sole use of the computer for a limited period of time and would arrive at a scheduled time with program and data on punched paper cards and/or punched tape. The program would be loaded into the machine, and the machine would be set to work until the program completed or crashed. Programs could generally be debugged via a front panel using toggle switches and panel lights. It is said that Alan Turing was a master of this on the early Manchester Mark 1 machine, and he was already deriving the primitive conception of an operating system from the principles of the Universal Turing machine.[4]
Later machines came with libraries of programs, which would be linked to a user's program to assist in operations such as input and output and generating computer code from human-readable symbolic code. This was the genesis of the modern-day operating system. However, machines still ran a single job at a time. At Cambridge University in England the job queue was at one time a washing line from which tapes were hung with different colored clothes-pegs to indicate job-priority.[citation needed]
15 Business writing is different
Writing for a business audience is usually quite different than writing in the humanities, social sciences, or other academic disciplines. Business writing strives to be crisp and succinct rather than evocative or creative; it stresses specificity and accuracy. This distinction does not make business writing superior or inferior to other styles. Rather, it reflects the unique purpose and considerations involved when writing in a business context.
When you write a business document, you must assume that your audience has limited time in which to read it and is likely to skim. Your readers have an interest in what you say insofar as it affects their working world. They want to know the “bottom line”: the point you are making about a situation or problem and how they should respond.
Business writing varies from the conversational style often found in email messages to the more formal, legalistic style found in contracts. A style between these two extremes is appropriate for the majority of memos, emails, and letters. Writing that is too formal can alienate readers, and an attempt to be overly casual may come across as insincere or unprofessional. In business writing, as in all writing, you must know your audience.
In most cases, the business letter will be the first impression that you make on someone. Though business writing has become less formal over time, you should still take great care that your letter’s content is clear and that you have proofread it carefully.
16 Basic concepts used in text analysis processing
Basic concepts that are used in text analysis processing include annotators, analysis results, feature structure, type, type system, annotation, and common analysis structure.
Annotators contain the logic that analyzes a document and discovers and records descriptive data about the document as a whole (referred to as document metadata) and parts in the document. This descriptive data is referred to as analysis results. The analysis results annotate any contiguous substring (also referred to as span) of the text document. Ideally, the analysis results correspond to the information that you want to search for.
A feature structure is the underlying data structure that represents an analysis result. A feature structure is an attribute-value structure. Each feature structure is of a type and every type has a specified set of valid features or attributes (properties), much like a Java™ class. Features have a range type that indicates the type of value that the feature must have, such as String. All annotators in UIMA store data in feature structures.
For example, the text span "James Matthew Bloggs" might be spanned by an annotation of type Person with the features personName, age, nationality and profession.
17 Types of Codecs
Audio and video files are too large to be transmitted digitally. They are normally compressed into a digital signal and then transmitted. Codecs are programs capable of compressing and decompressing a digital signal. Codecs encode and decode data for transmission, storage or encryption. Codecs are used in video streaming and video conferencing, among other applications.
Lossy or Lossless Codecs
Lossy codecs are more common than lossless codecs. Lossy codecs compress data into small files, though there is a loss in quality of the data. Lossless codecs maintain data quality but do not reduce the data size by a large margin. Both these codecs are used to encode video, audio and speech files. Different lossy codecs are AAC, MP3, Vorbis, and lossy Windows Media Audio. FLAC, Monkey's Audio, Shorten, TTA, lossless Windows Media Audio and WavPack are examples of lossless codecs.
Speech and Audio Codecs
Speech codecs encode the different characteristics of voice, while audio codecs are used for music. Speech codecs look for speech patterns. Various speech codecs are µ-Law PCM, ACELP, A-Law PCM, AMR-NB, AMR-WB and DV Audio. Audio codecs include AAC, AIFF, AU and MP3.
Video Codecs
Video codecs are used encode and decode video files. Lossy compression is the most widely used compression technique. Video codecs try to balance compression size with quality of data. Huffyuv, DivX Pro Codec and x264 are different video codecs.
18 Control system
There are two common classes of control systems, with many variations and combinations: logic or sequential controls, and feedback or linear controls. There is also fuzzy logic, which attempts to combine some of the design simplicity of logic with the utility of linear control. Some devices or systems are inherently not controllable.The term "control system" may be applied to the essentially manual controls that allow an operator, for example, to close and open a hydraulic press, perhaps including logic so that it cannot be moved unless safety guards are in place.
An automatic sequential control system may trigger a series of mechanical actuators in the correct sequence to perform a task. For example various electric and pneumatic transducers may fold and glue a cardboard box, fill it with product and then seal it in an automatic packaging machine. Programmable logic controllers are used in many cases such as this, but several alternative technologies exist.
In the case of linear feedback systems, a control loop, including sensors, control algorithms and actuators, is arranged in such a fashion as to try to regulate a variable at a setpoint or reference value. An example of this may increase the fuel supply to a furnace when a measured temperature drops. PID controllers are common and effective in cases such as this. Control systems that include some sensing of the results they are trying to achieve are making use of feedback and so can, to some extent, adapt to varying circumstances. Open-loop control systems do not make use of feedback, and run only in pre-arranged ways.
19 High frequency
High frequency (also known as the Tesla high frequency current) was first developed in the late 1800's by renowned scientist Nikola Tesla. While it offers a number of functions, before the invention of 'modern' antibiotics it was largely used for medical purposes such as in the treatment of strep throat and other infections.
French biophysicist D'Arsonval also did early work in the area of electrotherapy. In 1892 he introduced the use of high frequency currents to treat diseases of the skin and mucous membranes. High frequency is also commonly referred to as the D'Arsonval high frequency current.
In the 1970's, European salons discovered the cosmetic and healing benefits of high frequency electrical stimulation on the skin and by 1980, the the technology became widely used in North American by skin care professionals. The safe, non-invasive technology was quickly found to be very beneficial in the treatment of many skin conditions ranging from acne to wrinkles.
Widely used by prestigious spas and professional salons throughout the world today, the application of high frequency has become an important component of many skin care treatment regimens, procedures and programs.
20 Developing of Telecommunications
I would like to tell you about telecommunications and their developing.
We can not deny the role of telecommunications in our life. The Internet, phones, telegraph, cell phones, radio, television are all the means of communication or telecommunication. Nowadays we live in information era, when information is the key and engine of progress. Our society needs perfect means of information exchange that is why all types of telecommunication are under the permanent developing.
Currently hundreds of millions of people use wireless communication means. Cell phone is no longer a symbol of prestige but a tool, which lets to use working time more effectively. Considering that the main service of a mobile connection operator is providing high quality connection, much attention in the telecommunication market is paid to the spectrum of services that cell network subscriber may receive.
Today we can easily connect to the Internet using our cell phone or to take a picture or to take a short movie, using our video cell phone.
Late in the nineteenth century, communication facilities were augmented by a new invention — telephone. In the USA its use expanded slowly and by 1900 the American Telephone and Telegraph Company controlled 855,000 telephones.
After 1900, telephone installations extended much more rapidly in all the wealthier countries. The number of telephones in use in the world grew at almost 100 per cent per decade. But long-distance telephone services gradually developed and began to compete with telegraphic business. A greater contribution to long-range communication came with the development of wireless technology.
Before the outbreak of the First World War wireless telegraphy was established as a means of regular communication with ships at sea and provided a valuable supplement to existing telegraph lines. In the next few years the telephone systems of all the chief countries were connected with each other by radio. Far more immediate was the influence that radio had through broadcasting and by television, which followed it at an interval of about twenty-five years.
Telephones are as much a part of infrastructure of our society as roads or electricity, and competition will make them cheaper. Losses from lower prices will be countered by higher usage. Most important of all, by cutting out the need to install costly cables and microwave transmitters, the new telephones could be a boon to the remote and poor regions of the earth. Even today, half the world's population lives more than two hours away from a telephone.
Satellite phones are not going to deliver all their benefits at once.
Lots of other new communication services — on-line film libraries, personal computers that can send video-clips and sound-bites as easily as they can be used for writing letters, terrestrial mobile-telephone systems cheap enough to replace old sets — are already technically possible.
21 Hardware
Hardware is best described as a device that is physically connected to your computer or something that can be physically touched. Most hardware will contain a circuit board, ICs, and other electronics. A perfect example of hardware is a computer monitor, which is an output device that lets you see what you're doing on the computer. Without any hardware, your computer would not exist, and software would not be able to run. In the image to the right, is a webcam and an example of an external hardware peripheral that allows users to make videos or pictures and transmit them over the Internet.
A hardware upgrade is any new hardware that replaces or adds to old hardware in the computer. A good example of a common hardware upgrade is a RAM upgrade, where the user is increasing the computers total memory, which will increase its overall speed and efficiency. Another good example is doing a video card upgrade, which is the act of removing the old video card and replacing it with a new video card that is much more capable than the previously installed video card, again increasing the capabilities of the computer.