key

1. In database terminology, a key value is that part of a row that makes the row unique from all other rows; for example, a SERIAL number. At least one such value must exist in any row; the most important is designated as the primary key.

See also column, rowid, table.

2. In application terminology, when speaking of the keyboard, a key is what the user presses to enter text or commands in the application. The actual keys of the keyboard (a, ESCAPE, ENTER) are often called physical keys to distinguish them from logical keys (which may be made up of a sequence of keys).

See also activation key, control character, ENTER key, function key, keyboard, logical key, mnemonic key, modifier key, RETURN key.