How does file compression/directory packaging work? How do .zip, .tar, and .tar.*z files work?

Question

anonymous · Answer

I just think of it being like a shadow of the actual file it the compression utility  drops a bunch of "binary" information but enough of the file still exists for the utility to rebuild the file upon extraction. all the different compression  protocols/utilities each use a different algorithm which does compression better or differently And those utilities came into existence  at different points in time but are still available for  backwards compatibility and personal preference ....another attribute worth noting is zip is generally windows and the others you mention are found on *nix systems. I like *.rar  on windows super tiny compression algorithm. Take this with a grain of salt I didn't look up anything just using my intuition and experience :)

rsmith6559 · Answer

FWIW, tar is an acronym for Tape ARchive.  It takes a list of files (or a directory tree) and writes them to an archive file which can then be passed into a compression program.

BTW, you may also want to check out compress and cpio, too for archives and bzip and bzip2 for compression.

anonymous · Answer

How deep do you want to study this question? This could be a lower-level graduate course by itself. The standard textbook on data compression seems to be "Introduction to Data Compression" by Khalid Sayood.

Did the Wikipedia article not help?