1. < networking > e-mail address .
2. < networking > Internet address .
3. < networking > MAC address .
4. An unsigned integer used to select one fundamental element of storage, usually known as a word from a computer's main memory or other storage device. The CPU outputs addresses on its address bus which may be connected to an address decoder , cache controller , memory management unit , and other devices.
While from a hardware point of view an address is indeed an integer most strongly typed programming languages disallow mixing integers and addresses, and indeed addresses of different data types. This is a fine example for syntactic salt : the compiler could work without it but makes writing bad programs more difficult.