encapsulation

1. The technique used by layered protocols in which a layer

adds header information to the protocol data unit (PDU) from

the layer above. As an example, in Internet terminology, a

packet would contain a header from the physical layer,

followed by a header from the network layer (IP), followed by

a header from the transport layer (TCP), followed by the

application protocol data.

2. The ability to provide users with a well-defined interface

to a set of functions in a way which hides their internal

workings. In object-oriented programming, the technique of

keeping together data structures and the methods (procedures)

which act on them.

(1998-09-07)