Secondary Storage

File Compression

Extracting a zip file. (Decompression)

File compression decreases the size of files and makes it easier for file transfer and storage as it saves space and requires less time to transfer. Files that have been compressed are called ZIP files. To reobtain compressed files programmes to decompress files are required.

Head Crash 

Head Crash Hard Disk

Head crash is also know as disk crash. This occurs when the head comes into contact with the disk and scratches it or burns it. Information is then loss, so it is important to operate hard disk drives in clean environments to avoid dust particles or smoke particles to enter the disk drive and cause the head that usually hovers several microinches above the disk to come into contact with the disk.

Internet Hard Drive

Internet hard drives provide the user the ability to access their stored documents from any computer that has access to the internet. It allows one to upload their documents into a remote hard drive, and allows retrieval of documents from any computer.

Optical Disc Drive

Optical Disc Drives

An optical disc drive is an area that allows optical discs to be inserted into the computer, and is usually built into the computer and pops out with the touch of a button. Most optical drives can play or record on many different disc formats. 

Solid-state Storage

Solid-state storage is similar to larga capacity, nonvolatile memory. Rather than magnetic or optical media, integrated circuits (ICs) are employed. Solid-state storage is non-volatile and allows removal of stored items.

Input and Output

Ergonomic Keyboard

Ergonomic Keyboard

Ergonomic keyboards are designed to reduce muscle strain from repetitive muscle movements from interacting with the computer, such as repeatedly clicking and typing for prolonged periods of time. Ergonomic keyboards are made in a way to lower the risk of injuring oneself from the strains of these repetitive actions that may be required from one's job.

Ink-jet Printer

Ink-jet Printer

Ink-jet printers work on the basis of spraying tiny droplets of ink on paper. The ink is ionized, and the direction of spray is directed by magnetized plates. The tiny dots of colour are extremely small and the distance between each dot is so minimal that it usually goes unnoticed by the human eye. The size of the dots vary from 50 to 60 microns, which is smaller than even the diameter of the human hair, which is 70 microns.

Laser Printer

Inside a Laser Printer

Laser Printer

Static electricity is the primary principle behind the workings of a laser printer, and it is used as a "temporary glue". A revolving drum is often used as the core component, and it is highly photoconductive. A tiny laser beam is shot at the paper as the drum revolves, producing an electrostatic image. Then, the drum is coated by black powder called toner. This clings to negatively charged areas of the drum in the same image as the one drawn on the paper, and the paper is then rolled around the paper before being detached to absorb the image onto it, also using positively and negatively charged ions to do so.

Magnetic-ink Character Recognition (MICR)

MICR fonts

MICR-reading machine

MICR is a technique applied to read specially printed in magnetic-ink characters and then quickly and effectively inputting them into a computer. It is often used in banking because MICR can be read by machines far faster and far more accurate than any human and system can achieve, so they are usually used to read characters and codes on cheques.

Optical-character Recognition (OCR)

OCR Programme

Before using the OCR, the material has to be scanned first with an optical scanner to read in the page as a bitmap. Then, OCR software is used to tell between images and text and the letters used by light and dark areas. OCR can be said as the "guessing" of letters as many techniques and even algorithms are applied to search for matches of image scanned to letters known, hence it is sometimes inaccurate.

Optical-mark Recognition (OMR)

OMR sheet

To extract data from marked fields such as fill-in fields and printed forms. Predefined positions and records where marks are made on the forms are identified by the OMR, and since it does not require character recognition ability it is able to process forms and surveys with fill-in fields accurately at very fast rates.

Basic Application Software

Graphical User Interface (GUI)

GUI is a type of user interface that allows interaction of users with programs in more ways than typing. A GUI offers graphical icons, and visual indicators, as opposed to text-based interfaces, typed command labels or text navigation to fully represent the information and actions available to a user.

Word Processor

A word processor is a computer application used for the production of any sort of printable material. It provides the user with tools needed to compose, edit, format, and sometimes to print any sort of printable material.

Spreadsheet

Spreadsheets are computer applications that simulates a paper, accounting worksheet. It is made up of many cells and a formula defines how the content of a cell is calculated. Spreadsheets are used for financial information because of their ability to re-calculate the entire sheet automatically when changes to any single cell is made.

Database Management System (DBMS)

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. DBMS controls organization, storage, management, and retrieval of data in a database.

Utility Suites

Utility suites includes a variety of programs designed to make computing easier and safer, Two of the best known are Norton SystemWorks and Norton Internet Security Suite.

Specialized Application Software

Audio Editing Software

GarageBand, an audio editing software

Audio Editing Softwares are programs for manipulating digital audio. It allows for recording of audio, editing of start and stop time on sounds, audio fading in and out, mixing multiple sounds, applying simple or advanced effects or filters, playback sound after mixing, and converting sounds between different audio file formats. 

Bitmap Image

A bitmap is a type of memory organization or image file format used to store digital images. The term is derived from computer terminology, meaning a map of bits, a spatially mapped array of bits. It means one bit per pixel. It cannot be stretched or else the image gets distorted and pixelated. 

Desktop Publishing Program

Desktop publishing is the use of the computer and software to create visual displays of information and ideas. Desktop publishing documents may be for commercial or desktop printing or electronic distribution including PDF, slide shows, e-mail newsletters, and the web. 

HTML Editors

A HTML editor is an authoring software program that is used to create content for web sites. HTML software is easy to use since it has a feature known as WYSIWYG. Certain editors also provide word processing GUI enabling users to create HTML documents without any knowledge of HTML codes. 

Image Editors

This is a program that allows people to manipulate visual images on a computer. They can be classified into two distinct categories, which are bitmap and vector graphics. Although it is simple to convert vector graphics to bitmap, it is hard to do it the other way around. 

Vector Image

These images utilize geometrical primitives such as points, lines, curves, shapes, or polygons, which are all based on mathematical equations to represent images in computer graphics. Advantages are vector images can be resized without quality loss, but they are not appropriate for producing realistic images, because they have solid colour and gradient variation in the image. 

Multimedia

Multimedia is multiple forms of media integrated together. Media can be text, graphics, audio, animation, video, data, etc. Besides that, it can also stand for interactive types of media such as video games, CD ROMs that teach foreign languages, or an information kiosk at a subway terminal. 

The System Unit

Flash Memory

Flash Memory Card

Sometimes known as Flash RAM, it is constantly-powered nonvolatile memory, able to be erased and reprogrammed in units of memory known as blocks. It also prevents loss of information when the power supply is shut off. It is used by digital cellular phones, digital cameras, LAN switches, PC Cards for notebook computers, digital set-up boxes, embedded controllers. and other devices.

Graphic Cards

Graphic Cards

The graphics components are the part of your computer that control and enhance how graphics (pictures, videos, programs, animation, 3D) are displayed on your computer screen. The graphic components are usually on a separate card that plugs into a slot on the motherboard, that's why the graphic components are commonly called graphic cards. Sometimes the graphics card components are build directly into the motherboard.

Sound Card

Sound Cards

An expansion board that enables a computer to manipulate and output sounds. Sound cards are common in most modern personal computers. It allows sound output 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)

Network Interface Cards

It is the most important PC device. It is a card that is installed in a computer so that it can be connected to a network. Personal computers and workstations on a local area network (LAN) typically contain a network interface card specifically designed for the LAN transmission technology. Network interface cards provide a dedicated, full-time connection to a network.



Plug & Play

Microsoft Plug & Play Laptop Remote Control

Plug and Play (PnP) is a capability developed by Microsoft for its Windows 95 and later operating systems that gives users the ability to plug a device into a computer and have the computer recognize that the device is there. In many earlier computer systems, the user was required to explicitly tell the operating system when a new device had been added. However, this is no longer required with the PnP technology being introduced into the new systems. 

Bus Line



The bus lines are the communicating electronic lines that connect different parts of the CPU to various other parts. In addition, the bus lines also link the CPU to different parts on the system board of your computer. The data flows in the form of bits along the bus lines. The bus lines are like multilane pathways which means that the more bus lines are on the system the greater is the rate of transfer of data along the bus, which means that the computer can run efficiently and will perform the operations at a faster rate.

HDMI

HDMI Cable

HDMI stands for High-Definition Multimedia Interface. HDMI is an uncompressed, all-digital signal audio/video interface with 5 Gbps of available bandwidth. It contains 19 wires wrapped in a single cable that resembles a USB wire. The primary use of the HDMI wire is to transmit digital signals from a compatible digital audio/video source. It also carries compressed audio formats.

Cache Memory



Cache Memory Chip



Cache memory is random access memory (RAM) that a computer microprocessor can access more quickly than it can access regular RAM. As the microprocessor processes data, it looks first in the cache memory and if it finds the data there (from a previous reading of data), it does not have to do the more time-consuming reading of data from larger memory.