Wednesday, June 15, 2011

Secondary Storage

Disk Caching

In computer engineering, a cache is a component that transparently stores data so that future requests for that data can be served faster. 

File Compression / File Decompression

In computer science and information theory, data compressionsource coding or bit-rate reduction is the process of encoding information using fewer bits than the original representation would use.

Internet Hard Drive

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. Similar to depositing money into your bank account, and later withdrawing that same money from any ATM machine, an Internet hard drive will allow you to "deposit" your computer files into a remote hard drive, and then later access those very same files from any other computer.


Optical Disc Drive

In computing, an optical disc drive (ODD) is a disk drive that uses laser light or electromagnetic waves near the light spectrum as part of the process of reading or writing data to or from optical discs.


Solid-state storage

A solid-state drive (SSD) is a data storage device that uses solid-state memory to store persistent data with the intention of providing access in the same manner of a traditional block i/o hard disk drive.


Tuesday, June 14, 2011

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. Typically such keyboards are constructed in a V shape, to allow right and left hands to type at a slight angle more natural to the human form.

Inkjet Printer

An inkjet printer is a type of computer printer that creates a digital image by propelling droplets of ink onto paper. Inkjet printers are the most commonly used type of printer and range from small inexpensive consumer models to very large professional machines, that can cost up to thousands of dollars.

Laser Printer

laser printer is a common type of computer printer that rapidly produces high quality text and graphics on plain paper.

Magnetic Ink Character Recognition

Magnetic Ink Character Recognition, or MICR, is a character recognition technology used primarily by the banking industry to facilitate the processing of cheques.

Optical Character Recognition

Optical character recognition, usually abbreviated to OCR, is the mechanical or electronic translation of scanned images of handwritten, typewritten or printed text into machine-encoded text. It is widely used to convert books and documents into electronic files, to computerize a record-keeping system in an office, or to publish the text on a website.

Optical Mark Recognition

Optical Mark Recognition (also called Optical Mark Reading and OMR) is the process of capturing human-marked data from document forms such as surveys and tests.

Wednesday, May 25, 2011

System Unit


Random-access memory (RAM) is a form of computer data storage. Today, it takes the form of integrated circuits that allow stored data to be accessed in any order with a worst case performance of constant time. Strictly speaking, modern types of DRAM are therefore not random access, as data is read in bursts, although the name DRAM / RAM has stuck. However, many types of SRAM, ROM, OTP, and NOR flash are still random access even in a strict sense. RAM is often associated with volatile types of memory (such as DRAM memory modules), where its stored information is lost if the power is removed. Many other types of non-volatile memory are RAM as well, including most types of ROM and a type of flash memory called NOR-Flash. The first RAM modules to come into the market were created in 1951 and were sold until the late 1960s and early 1970s. However, other memory devices (magnetic tapes, disks) can access the storage data in a predetermined order, because mechanical designs only allow this.

Cache Memory

A CPU cache is a cache used by the central processing unit of a computer to reduce the average time to access memory. The cache is a smaller, faster memory which stores copies of the data from the most frequently used main memory locations. As long as most memory accesses are cached memory locations, the average latency of memory accesses will be closer to the cache latency than to the latency of main memory.


Read-only memory (ROM) is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware (software that is very closely tied to specific hardware, and unlikely to need frequent updates).

Flash Memory

Flash memory is a non-volatile computer storage chip that can be electrically erased and reprogrammed. It is primarily used in memory cards, USB flash drives, MP3 players and solid-state drives for general storage and transfer of data between computers and other digital products.

Graphics Card

A video card, video adapter, graphics accelerator card, display adapter, or graphics cardis an expansion card whose function is to generate output images to a display. Most video cards offer added functions, such as accelerated rendering of 3D scenes and 2D graphics, video capture, TV-tuner adapter, MPEG-2/MPEG-4 decoding, FireWire, light pen, TV output, or the ability to connect multiple monitors (multi-monitor). Other modern high performance video cards are used for more graphically demanding purposes, such as PC games.

Sound Card

A sound card (also known as an audio card) is an internal computer expansion card that facilitates the input and output of audio signals to and from a computer under control of computer programs. The term sound card is also applied to external audio interfaces that use software to generate sound, as opposed to using hardware inside the PC. Typical uses of sound cards include providing the audio component for multimedia applications such as music composition, editing video or audio, presentation, education and entertainment (games) and video projection. Many computers have sound capabilities built in, while others require additional expansion cards to provide for audio capability.

Network Interface Card

A network interface controller (also known as a network interface card, network adapter,LAN adapter and by similar terms) is a computer hardware component that connects a computer to a computer network.
Plug and Play

Serial Port

In computing, a serial port is a serial communication physical interface through which information transfers in or out one bit at a time (contrast parallel port). Throughout most of the history of personal computers, data transfer through serial ports connected the computer to devices such as terminals and various peripherals.
Parallel port

Universal Serial Bus Port

Universal Serial Bus (USB) is a specification to establish communication between devices and a host controller (usually a personal computer), developed and invented by Ajay Bhatt, while working for Intel. USB has effectively replaced a variety of interfaces such as serial and parallel ports.

Firewire port

The IEEE 1394 interface is a serial bus interface standard for high-speed communications and isochronous real-time data transfer, frequently used by personal computers, as well as in digital audio, digital video, automotive, and aeronautics applications. The interface is also known by the brand names of FireWire (Apple), i.LINK (Sony), and Lynx (Texas Instruments). IEEE 1394 replaced parallel SCSI in many applications, because of lower implementation costs and a simplified, more adaptable cabling system. The 1394 standard also defines a backplane interface, though this is not as widely used.

Ethernet port

Ethernet is a family of frame-based computer networking technologies for local area networks (LAN). It defines a number of wiring and signaling standards for the Physical Layer of thestandard networking model as well as a common addressing format and a variety of Medium Access Control procedures at the lower part of the Data Link Layer.

High Definition Multimedia Interface

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, DVD players, HD DVD players, Blu-ray Disc players, AVCHD camcorders, personal computers (PCs), video game consoles such as the PlayStation 3 and Xbox 360, and AV receivers) to compatible digital audio devices, computer monitors, video projectors, and digital televisions.

Wednesday, April 27, 2011

Basic and Specialized Software Application

Graphical User Interface (GUI)

GUI is an Interface that allows users to interact with their machines or devices using graphics and images rather than text, which is called "command line" interface.
Basically, on a GUI, everything is represented to make the system as user friendly as possible.
For example, on windows, the graphical user interface utilizes icons and windows as their main
user interface.

Ubuntu 10.10 User Interface
 Word Processor

Word processors are computer applications used to produce any type of printable material.
Microsoft Word is the most widely used word processing software. Microsoft estimates that over 500,000,000 people use the Microsoft Office suite, which includes Word.


A spreadsheet is a computer application that simulates a paper, accounting worksheet. It displays multiple cells usually in a two-dimensional matrix or grid consisting of rows and columns. Each cell contains alphanumeric text, numeric values or formulas. A formula defines how the content of that cell is to be calculated from the contents of any other cell (or combination of cells) each time any cell is updated. Spreadsheets are frequently used for financial information because of their ability to re-calculate the entire sheet automatically after a change to a single cell is made. A pseudo third dimension to the matrix is sometimes applied as another layer, or layers/sheets, of two-dimensional data.

Microsoft Excel

A Database Management System (DBMS) is a set of computer programs that controls the creation, maintenance, and the use of a database. It allows organizations to place control of database development in the hands of database administrators (DBAs) and other specialists. A DBMS is a system software package that helps the use of integrated collection of data records and files known as databases. It allows different user application programs to easily access the same database.

Utility Suites

A software suite or application suite is a collection of computer programs, usually application software and programming software of related functionality, often sharing a more-or-less common user interface and some ability to smoothly exchange data with each other.
Sometimes software makers introduce "suites" that are little more than repackaged versions of older programs offered at a lower price. MS Office is one of  the most well knowned utility suites.

Web Authoring

A category of software that enables the user to develop a Web site in a desktop publishing format. The software will generate the required HTML coding for the layout of the Web pages based on what the user designs.

Audio Editing Software

A digital audio editor is a computer application for audio editing, i.e. manipulating digital audio. Digital audio editors are the main software component of a digital audio workstation. An example of an Audio Editing Software is Audacity.

Abbleton Live, a Mac based Audio Editor
Bitmap Image

A bitmap or pixmap is a type of memory organization or image file format used to store digital images. The term bitmap comes from the computer programming terminology, meaning just a map of bits, a spatially mapped array of bits. Now, along with pixmap, it commonly refers to the similar concept of a spatially mapped array of pixels. Raster images in general may be referred to as bitmaps or pixmaps, whether synthetic or photographic, in files or memory.

Desktop Publishing Program

Desktop publishing (also known as DTP) combines a personal computer and WYSIWYG page layout software to create publication documents on a computer for either large scale publishing or small scale local multifunction peripheral output and distribution. An example of a DTP software is Adobe FrameMaker.

HTML Editor

An HTML editor is a software application for creating web pages. Although the HTML markup of a web page can be written with any text editor, specialized HTML editors can offer convenience and added functionality. A good example of this is Microsoft Frontpage.

Image Editor

An image editing software is a program or collection of programs that enable a person to manipulate visual images on a computer. The use of a swatch is a palette of active colours that are selected and rearranged by the preference of the user. A swatch may be used in a program or be part of the universal palette on an operating system, it is used to change the colour of a project, that may be text, image or video editing.
Several graphics programs support animation, or digital video. Adobe Photoshop is great example of an Image Edition Software.


Multimedia is media and content that uses a combination of different content forms. The term can be used as a noun (a medium with multiple content forms) or as an adjective describing a medium as having multiple content forms. The term is used in contrast to media which only use traditional forms of printed or hand-produced material. Multimedia includes a combination of text, audio, still images, animation, video, and interactivity content forms.
Vector Image

Vector graphics is the use of geometrical primitives such as points, lines, curves, and shapes or polygon(s), which are all based on mathematical equations, to represent images in computer graphics.

Vector and Normal image comparison