A modem is a device for connecting a computer via telephone lines to other computers. These and similar devices areperipherals

The physical machinery of computers: processing and memory devices, and peripher­als, are together referred to as hardware (... the central processor (which can perform a huge number of calculations very quickly) and the 'peripherals' of the computer, such as keyboard, monitor, screen, disc drives and ex­ternal data links). Modem airliners use a mix of traditional instruments and computer-generated ones that appear on a VDU screen. Computers which use an electronic mouse to point at pictures on the screen are easier for the keyboard-shy. Today, because the personal computer and the laser -printer are mass produced and work using cheap electronic components, anybody can publish text of almost professional quality for a small investment.

They predict that magazine publishers will soon start worrying about the boom in the sales of desktop publishing software and optical scanners which can copy text and images into DTP documents. Anybody equipped with a computer, modem and telephone line can send and receive unlimited information around the world almost for free.

One of the banks spent millions of dollars on new computer hardware, only to find subsequently that only one software program ran on it.

To function at all, a computer needs an operating system program. Some operating systems require users to type in commands to tell the computer what they want to do.

Many computers use a graphical interface or point-and-click interface such as Windows. Icons are symbols representing the different peripherals, programs, and files. Functions are activated by selecting a particular icon with the mouse.

Some interfaces allow plug-and-play, the possibility of connecting new hardware to the computer without having to adjust or configure the system to take the new hardware into account: the interface program recognises the hardware automatically.

The quality of the operating system determines how useful the computer is. The more effective it is, the more programs it can run at once and the more efficiently it uses the finite resources of the processor....Microsoft, the company that gave the world the ubiquitous Windows graphical inter­face. Windows popularised the mouse-driven point-and-click interface first seen on the Apple Macintosh.

Files and programs are arranged into icons so that the user can see at a glance what files are available and what programs are running.

PC games required users to enter complicated DOS commands to configure audio, video and graphics cards. The newly claimed 'plug and play' capability for Windows 95 stems from a new collection of Microsoft programs called DirectX that solves the memory problems of previous Windows versions.