(1) An Internet Protocol (IP) datagram that contains only a portion of the user data from a larger IP datagram.
(2) The smallest unit of file system disk space allocation. A fragment can be 512, 1024, 2048, or 4096 bytes in size. The fragment size is defined when a file system is created.
(3) The space allocated for an amount of data too small to require a full block. A fragment consists of one or more subblocks.