A tar file is uncompressed, it basically tacks lots of files (which can be in directories) together into one file, keeping their permissions, ownership, directory info etc. This single file can then be compressed with gzip (.gz).
I don\'t think that there is a Windows equivalent, just that tar & gzip are about the same as zipping something (you can also zip under Linux if you so desire).
Offroadgeek\'s post is wrong.
The switches are:
z - uncompress using gunzip
x - extract
c - create (so you only use one of these)
f - it\'s a file (this is always needed, don\'t ask)
v - be verbose
e.g.
tar -zxvf somefiles.tar.gz (extract from tar.gz)
tar -xvf somefiles.tar (extract from tar)
tar -cvf somefiles.tar ./getfilesfromhere/* (create tar file)
Si