没有什么本质区别，都是将输入的文件按一定大小的字节进行拆分。关于split在linux下的说明：

$ info coreutils 'split invocation'

File: coreutils.info,  Node: split invocation,  Next: csplit invocation,  Prev: tail invocation,  Up: Output of parts of files

5.3 'split': Split a file into pieces.
======================================

'split' creates output files containing consecutive or interleaved
sections of INPUT (standard input if none is given or INPUT is '-').
Synopsis:

     split [OPTION] [INPUT [PREFIX]]

   By default, 'split' puts 1000 lines of INPUT (or whatever is left
over for the last section), into each output file.