Just fyi, TGZ is the same as tar.gz, which is a unix format which actually is two things, something.tar has no compression, tar stands for tape-archive (very old name), and it basically means bundle a bunch of files up into 1 file. something.tar.gz means its tar'ed first, then gzipped, which is a pretty darn good compression. On 'nix you use gunzip to uncompress this not unzip. Anyway winzip and many other 3rd party apps just hides all this from you and opens them anyway

Compression is actually better with tgz than zip, and also it can keep user and file permission information which zip does not.
Anyway, know you know more than you ever wanted to
