Home Computer: Jargon buster

Button: on a mouse, the part pressed to execute an instruction; in a screen window, a small icon, representing an instruction - to turn words into bold text or whatever - which can be activated by the mouse or from the keyboard.

Graphical user interface: Point-and-click operating systems which display icons or menu lists of instruction. These can be selected by moving an arrow on screen to point at the required instruction and activated by clicking on the mouse.

Icon: a small pictogram or logo in windows systems that represents an instruction to the computer.

Macro: A series of instructions memorised as a tiny program and activated by a mouse click or one key-stroke of a special function key. A word processing macro, for instance, might load a text file, change it into a particular typeface and perform a word count.

Memory management: A problem with the PC's venerable Dos operating system is that it can only use 640 kilobytes (thousand bytes) of main memory (ram) for processing data, even if the machine has 4 megabytes (million bytes) or more - the extra ram is used as a sort of super-fast storage area. As certain basic operations of the computer have to reside almost permanently the core 640K of main memory, it cuts down the amount available to programs that need a lot of processing power, particularly graphics programs and games. A memory management program makes as much ram as possible available to such programs so that they can work.

Menu bar: a bar across the screen from which menus or lists of instructions can be selected, usually by clicking on a menu name such as 'file' which will make a further list of instructions drop down the screen over what is already displayed. An instruction on the list can be activated by pointing to it with a mouse and clicking or by using the keyboard.

Ribbon: A strip of icons across the screen to initiate common commands such as turn into bold text.

Scroll bars: Shaded bars at the side and bottom of a screen in a windows program which allows the user to move up and down or from side to side in a document, to get exactly the portion required on screen.

Wysiwyg: Acronym for 'what you see is what you get'; what is displayed on the screen - text typefaces and sizes, graphics, pictures - will look exactly like the printed version of the document.