A set of input keys on a personal computer or computer terminal. Along with the standard letter keys on a typewriter, computer keyboards have keys for cursor movement and entering commands as outlined below. See keyboard. Enter (Return) Key The Enter key ends a line or paragraph of text, and in many cases activates the next function in the program. Cursor/Arrow and Modifier Keys The four Arrow keys pressed alone move the cursor on screen one line or character. Used with modifier keys, they move the cursor in bigger jumps such as top of document, end of line, etc. In Windows, Shift, Control, Alt and the Windows key are the modifier keys that are held down while pressing the Arrow keys. In the Mac, Shift, Control, Alt/Option and Command are used. See modifier key, Control key and Command key. Escape Key (Esc) Commonly used to exit or cancel the current mode such as exiting from a menu, the Esc key may also be used to clear an area or repeat a function such as redrawing the screen. Numeric Lock Locks a combination number/cursor keypad into numeric mode only. Home and End Keys Commonly used to move the cursor to the left or right side of the current line or to the top and bottom of a document. Often used with a modifier key; for example, Control-Home may jump the cursor to the top of the file. Page Up/Page Down Keys Used to move the cursor up and down a page, screen or frame. On laptop keyboards, these keys are often used with the Fn modifier key. See Fn key. Function Keys Used to call up a menu or perform a function, they are located in a cluster on the left side or in a row across the top of the keyboard (F1, F2, etc.). Function keys are often used with modifier keys to extend their capabilities. Backspace Key Used to erase the character to the left of the cursor. The wide, typewriter-style Backspace key is preferred. Delete Key (Del) Used to erase the character to the right of the cursor. Modifier keys affect larger text segments; for example, Control-Del or Alt-Del generally deletes a word. Insert Key (Ins) Toggles between insert mode and overtype mode. Ins may also used to "paste" text from the clipboard. Repeating Keys Most computer keys repeat when held down. If you hold a key command combination down, the command will be entered several times. For example, Control-Del or Alt-Del will continue to delete words for as long as the keys are held down. Audible Feedback Keys may cause a click or beep to be heard from the computer when pressed to acknowledge that the character has been entered. This sound is generally not adjustable for personal preference.