Hard Disk A computer's high -speed storage device. It contains the operating system, the programs and all the files. The hard disk is reffered to as the 'C drive'.

Hardware The physical pars of a computer, monitor,keyboard, mouse and other devices such as the printer, scanner and speakers. 

Header The area at the top of a page in a document. Text entered in the header (such as title) appears on every page of the documentunless you specify otherwise. 

Help key Usually the F1 key. Pressed to access advice and information on how to perform the task the user is currently engaged in. 

Highlight To select a word, a section of text or a group of cells, by clicking and dragging over them using the mouse.