A series of techniques used for the reduction of space, bandwidth,cost,transmission,generating time,and the storage of data.These techniques are designed to eliminate repetition, remove irrelevances,and employ special coding techniques.

• 在减少空间和时间消耗、缩小频带宽度、压缩存储量和传输量、降低成本等方面采用的一系列技术。如消除重复、去掉无关项、使用特殊编码技术等。