The System Unit

Flash Memory 
A special type of EEPROM that can be erased and reprogrammed in blocks instead of one byte at a time. Many modern PCs have their BIOS stored on a flash memory chip so that it can easily be updated if necessary.  Flash memory is also popular in modems because it enables the modem manufacturer to support new protocols as they become standardized. Flash memory is also called flash RAM.

Graphic Cards

A graphic card (also video card) is a piece of hardware installed in a computer that is responsible for rendering the image on the computer’s monitor or display screen. The first consideration when buying a graphics card is to be sure it is capable of displaying the best resolution the monitor can support. The second consideration is on-board memory. A graphics card must work very hard to render images to the screen. Unlike text files, graphics images are much larger files consisting of great amounts of data that must be processed by the graphics or video card.

Sound Cards

An expansion board that enables a computer to manipulate and output sounds. Sound cards are necessary for nearly all CD-ROMs and have become commonplace on modern personal computers. Sound cards enable the computer to output sound through speakers connected to the board, to record sound input from a microphone connected to the computer, and manipulate sound stored on a disk.

Network Interface Card (NIC)

Often abbreviated as NIC, an expansion board you insert into a computer so the computer can be connected to a network. Most NICs are designed for a particular type of network, protocol, and media, although some can serve multiple networks.

Plug and Play
Refers to the ability of a computer system to automatically configure expansion boards and other devices. You should be able to plug in a device and play with it, without worrying about setting DIP switches, jumpers, and other configuration elements. Since the introduction of the NuBus, the Apple Macintosh has been a plug-and-play computer.

Bus Line

In computer architecture, a bus is a subsystem that transfers data between computer components inside a computer or between computers. Early computer buses were literally parallel electrical buses with multiple connections, but the term is now used for any physical arrangement that provides the same logical functionality as a parallel electrical bus.

HDMI

HDMI (High-Definition Multimedia Interface) is a compact audio/video interface for transmitting uncompressed digital data. It is a digital alternative to consumer analog standards, such as radio frequency (RF) coaxial cable, composite video, S-Video, SCART, component video, D-Terminal, or VGA. HDMI connects digital audio/video sources (such as set-top boxes, upconvert DVD players, HD DVD players, Blu-ray Disc players, AVCHD camcorders, personal computers (PCs), video game consoles such as the PlayStation 3, Xbox 360, and AV receivers) to compatible digital audio devices, computer monitors, video projectors, and digital televisions.

 

Cache Memory
A memory cache, sometimes called a cache store or RAM cache, is a portion of memory made of high-speed static RAM (SRAM) instead of the slower and cheaper dynamic RAM (DRAM) used for main memory. Memory caching is effective because most programs access the same data or instructions over and over. By keeping as much of this information as possible in SRAM, the computer avoids accessing the slower DRAM.

Secondary Storage

File Compression


Compression is useful because it helps reduce the consumption of expensive resources, such as hard disk space or transmission bandwidth. On the downside, compressed data must be decompressed to be used, and this extra processing may be detrimental to some applications.

In computer science and information theory, data compression or source coding is the process of encoding information using fewer bits (or other information-bearing units) than an unencoded representation would use, through use of specific encoding schemes.



Head Crash

 A head crash usually means that the head has scratched or burned the disk. In a hard disk drive, the head normally hovers a few microinches from the disk. If the head becomes misaligned or if dust particles come between it and the disk, it can touch the disk. When this happens, you usually lose much of the data on the hard disk and will need to replace both the head and the disk. Head crashes are less common for floppy disks because the head touches the disk anyway under normal operation.

Another term for head crash is disk crash.

                                     Optical Disk Drive

 A storage medium from which data is read and to which it is written by lasers. Optical disks can store much more data up to 6 gigabytes (6 billion bytes) -- than most portable magnetic media, such as floppies. There are three basic types of optical disks:  CD-ROM, WORM, erasable.

These three technologies are not compatible with one another; each requires a different type of disk drive and disk. Even within one category, there are many competing formats, although CD-ROMs are relatively standardized.

Solid-State Storage

is a nonvolatile, removable storage medium that employs integrated circuits rather than magnetic or optical media. It is the equivalent of large-capacity, nonvolatile memory. Examples include flash memory Universal Serial Bus (USB) devices and various proprietary removable packages intended to replace external hard drives.

                                     
                                      Internet Hard Drive

Since the advent of digital media, there has been a need to store and retrieve media. Internet hard drives have served to meet this need, offering a creative new solution to the issue of data storage.

The sole purpose of an Internet hard drive is to offer a means of accessing your computer files (pictures, documents, music, videos, etc.) from any computer, as long as that computer has access to the Internet.

Unlike your local hard drive, which may have a limited storage capacity, a competitive Internet hard drive provider will offer virtually unlimited disk space.

Input And Output

Ergonomic Keyboard

An ergonomic keyboard is a computer keyboard designed with ergonomic considerations to minimize muscle strain and a host of related problems.

 

                                                                    
                                                                     Ink-Jet Printer

 

 type of printer that works by spraying ionized ink at a sheet of paper. Magnetized plates in the ink's path direct the ink onto the paper in the desired shapes. Ink-jet printers are capable of producing high quality print approaching that produced by laser printers. A typical ink-jet printer provides a resolution of 300 dots per inch, although some newer models offer higher resolutions.

Laser Printer


Electrostatic printer that focuses a laser beam to form images that are transferred to paper electrostatically.

Laser printer is a type of printer that utilizes a laser beam to produce an image on a drum. The light of the laser alters the electrical charge on the drum wherever it hits. The drum is then rolled through a reservoir of toner, which is picked up by the charged portions of the drum. Finally, the toner is transferred to the paper through a combination of heat and pressure. This is also the way copy machines work.

Magnetic-ink character recognition (MICR)

Magnetic Ink Character Recognition, or MICR, is a character recognition technology used primarily by the banking industry to facilitate the processing of cheques. The technology allows computers to read information (such as account numbers) off of printed documents. Unlike barcodes or similar technologies, however, MICR codes can be easily read by humans.

Optical-Character Recognition (OCR)

Optical Character Recognition (OCR) is a process of converting printed materials into text or word processing files that can be easily edited and stored. The technology has enabled such materials to be stored using much less storage space than the hard copy materials. OCR technology has made a huge impact on the way information is stored, shared and edited. Prior to optical character recognition, if someone wanted to turn a book into a word processing file, each page would have to be typed word for word.

Optical-Mark Recognition


Short for optical mark recognition, the technology of electronically extracting intended data from marked fields, such as checkboxes and fill-infields, on printed forms. OMR technology scans a printed form and reads predefined positions and records where marks are made on the form. This technology is useful for applications in which large numbers of hand-filled forms need to be processed quickly and with great accuracy, such as surveys, reply cards, questionnaires and ballots. A common OMR application is the use of "bubble sheets" for multiple-choice tests used by schools.

Specialized Application Software

Audio Editing Software


a computer application for audio editing, i.e. manipulating digital audio. Digital audio editors are the main software component of a digital audio workstation.


Editors designed for use with music typically allow the user to do the following:

• Record audio from one or more inputs and store recordings in the computer's memory as digital audio

• Edit the start time, stop time, and duration of any sound on the audio timeline

• Fade into or out of a clip (e.g. an S-fade out during applause after a performance), or between clips (e.g. crossfading between takes)

• Mix multiple sound sources/tracks, combine them at various volume levels and pan from channel to channel to one or more output tracks

• Apply simple or advanced effects or filters, including compression, expansion, flanging, reverb, audio noise reduction and equalization to change the audio

• Playback sound (often after being mixed) that can be sent to one or more outputs, such as speakers, additional processors, or a recording medium

• Conversion between different audio file formats, or between different sound quality levels

Bitmap Image


A representation, consisting of rows and columns of dots, of a graphics image in computer memory. The value of each dot (whether it is filled in or not) is stored in one or more bits of data. For simple monochrome images, one bit is sufficient to represent each dot, but for colors and shades of gray, each dot requires more than one bit of data. The more bits used to represent a dot, the more colors and shades of gray that can be represented.

Desktop Publishing Program


Using a personal computer or workstation to produce high-quality printed documents. A desktop publishing system allows you to use different typefaces, specify various margins and justifications, and embed illustrations and graphs directly into the text. The most powerful desktop publishing systems enable you to create illustrations, while less powerful systems let you insert illustrations created by other programs.



HTML editors


Also called an authoring tool, an HTML editor is a software program that inserts HTML code as you create a HTML file. Some editors will provide a word processing GUI enabling users to create HTML documents without knowing any HTML code.

Image Editors


A graphics program that provides a variety of special features for altering bit-mapped images. The difference between image editors and paint programs is not always clear-cut, but in general image editors are specialized for modifying bit-mapped images, such as scanned photographs, whereas paint programs are specialized for creating images.

In addition to offering a host of filters and image transformation algorithms, image editors also enable you to create and superimpose layers.

Multimedia


The use of computers to present text, graphics, video, animation, and sound in an integrated way. Long touted as the future revolution in computing, multimedia applications were, until the mid-90s, uncommon due to the expensive hardware required. With increases in performance and decreases in price, however, multimedia is now commonplace. Nearly all PCs are capable of displaying video, though the resolution available depends on the power of the computer's video adapter and CPU.

Vector Image


Same as object-oriented graphics, refers to software and hardware that use geometrical formulas to represent images. The other method for representing graphical images is through bit maps, in which the image is composed of a pattern of dots.


Vector-oriented images are more flexible than bit maps because they can be resized and stretched. In addition, images stored as vectors look better on devices (monitors and printers) with higher resolution, whereas bit-mapped images always appear the same regardless of a device's resolution.

Basic Application Software

Graphical User Interface (GUI)

A program interface that takes advantage of the computer's graphics capabilities to make the program easier to use. Well-designed graphical user interfaces can free the user from learning complex command languages. On the other hand, many users find that they work more effectively with a command-driven interface, especially if they already know the command language.

 Word Processor

Using a computer to create, edit, and print documents. Of all computer applications, word processing is the most common. To perform word processing, you need a computer, a special program called a word processor, and a printer. A word processor enables you to create a document, store it electronically on a disk, display it on a screen, modify it by entering commands and characters from the keyboard, and print it on a printer.

The great advantage of word processing over using a typewriter is that you can make changes without retyping the entire document. If you make a typing mistake, you simply back up the cursor and correct your mistake.








 Spreadsheet

A table of values arranged in rows and columns. Each value can have a predefined relationship to the other values. If you change one value, therefore, you may need to change other values as well.

Once you have defined the cells and the formulas for linking them together, you can enter your data. You can then modify selected values to see how all the other values change accordingly. This enables you to study various what-if scenarios.

 Database Management System (DBMS)

A database management system (DBMS), sometimes just called a database manager, is a program that lets one or more computer users create and access data in a database. The DBMS manages user requests (and requests from other programs) so that users and other programs are free from having to understand where the data is physically located on storage media and, in a multi-user system, who else may also be accessing the data.

Utility Suites

A kind of system software designed to help analyze, configure, optimize and maintain the computer. A single piece of utility software is usually called a utility (abbr. util) or tool.

Utility software should be contrasted with application software, which allows users to do things like creating text documents, playing games, listening to music or surfing the web.

The Internet, The Web and Electronic Commerce

What exactly is Javascript?

Javascript is a programming language that is used to make web pages interactive. It runs on your visitor's computer and so does not require constant downloads from your web site.

 

 

What do I need to run Javascript?

Javascript support is built right into web browsers. Provided that the visitors to your site are using web browsers that support Javascript (most do) and have Javascript enabled (it is by default) then your Javascript will run.

Do I need to learn Javascript to be able to use it?

No. There are plenty of Javascripts that have already been written that people have made available for you to plug straight into your web page. All you need to know to be able to use such scripts is how to paste the supplied code into the required places in your web page.

Applets

Applet: a small Java program that can be embedded in an HTML page. Applets differ from full-fledged Java applications in that they are not allowed to access certain resources on the local computer, such as files and serial devices (modems, printers, etc.), and are prohibited from communicating with most other computers across a network. The common rule is that an applet can only make an Internet connection to the computer from which the applet was sent.

Examples of Web-based Applets include:

• QuickTime movies
• Flash movies.
• Windows Media Player applets - used to display embedded video files in Internet Explorer (and other browsers that support the plugin).
• 3D-modelling display applets allowing a view of a model to be rotated and zoomed.
• Browser games can be applet-based, though some may develop into fully functional applications that require installation.

Filters

(1) A program that accepts a certain type of data as input, transforms it in some manner, and then outputs the transformed data. For example, a program that sorts names is a filter because it accepts the names in unsorted order, sorts them, and then outputs the sorted names.  Utilities that allow you to import or export data are also sometimes called filters.

(2) A pattern through which data is passed. Only data that matches the pattern is allowed to pass through the filter.

(3) In paint programs and image editors, a filter is an effect that can be applied to a bit map. Some filters mimic conventional photographic filters, but many transform images in unusual ways. A pointillism filter, for example, can make a digitized photograph look like a pointillistic painting.

Plug-ins

In computing, a plug-in (or plugin) is a set of software components that adds specific capabilities to a larger software application. If supported, plug-ins enable customizing the functionality of an application. For example, plug-ins are commonly used in web browsers to play video, scan for viruses, and display new file types. Well-known plug-ins examples include Adobe Flash Player and QuickTime.

 

  

Internet security

Internet security is a branch of computer security specifically related to the Internet. Its objective is to establish rules and measure to use against attacks over the Internet.

Securing Your Computer When Connected To The Internet !!!
 Internet security has become a serious issue for anyone connected to the net. Even if you don't think you have anything worth protecting on your computer, it's still important that you keep it locked down.

Even if your computer isn't used for anything critical you need to run security software such as an antivirus and a firewall.


These programs will keep your computer "hidden" from prying eyes over the internet, as well as protected from viruses and other malware that can be spread through email or other methods.

FTP - File Transfer Protocol

                               What is the File Transfer Protocol (FTP)?

In the language of the Internet, FTP refers to a network protocol responsible for transferring files from one computer to another over a TCP computer network or the Internet, which explains the origin of its name, formed as an acronym of File Transfer Protocol.

                                     What is the FTP commonly used for?

The most common use of FTP - for data transfer purposes, is of greatest help to users creating their websites on their personal computers due to the high flexibility levels it offers as far as the parameters of the computer-server connection are concerned.

                                                FTP- How does it work?

To take an advantage of FTP you must have an active Internet connection, a hosting server from/to where the files will be transferred and FTP account creation rights. All web hosting plans offered by NTC Hosting feature an integrated FTP Manager, allowing users to create several independent FTP accounts for their particular needs.

                                                            Wiki

Wiki is a piece of server software that allows users to freely create and edit Web page content using any Web browser. Wiki supports hyperlinks and has a simple text syntax for creating new pages and crosslinks between internal pages on the fly.

 

Wiki is unusual among group communication mechanisms in that it allows the organization of contributions to be edited in addition to the content itself.

 

                     URL

In computing, a Uniform Resource Locator (URL) is a Uniform Resource Identifier (URI) that specifies where an identified resource is available and the mechanism for retrieving it. In popular usage and in many technical documents and verbal discussions it is often incorrectly used as a synonym for URI.The best-known example of the use of URLs is for the addresses of web pages on the World Wide Web, such as http://www.example.com/.