(computer science) a graphic symbol (usually a simple picture) that denotes a program or a command or a data file or a concept in a graphical user interface
a code (a series of characters or digits) that must be entered in some way (typed or dialed or spoken) to get the use of something (a telephone line or a computer or a local area network etc.)
code consisting of a series of vertical bars of variable width that are scanned by a laser; printed on consumer product packages to identify the item for a computer that provides the price and registers inventory information