File Compression and Archiving with Gzip, Zip, and Tar
site: http://www.redhat.com/docs/manuals/linux/RHL-7.2-Manual/getting-started-guide/s1-zip-tar.html
Compressed files use less disk space and download faster than large, uncompressed files. You can compress Linux files with the open-source compression tool Gzip or with Zip, which is recognized by most operating systems.

HOWTO: Backup files with tar
site: http://lantech.geekvenue.net/chucktips/jason/chuck/994016279/index_html
TAR is the Unix Tape ARchive utility. It can be used to either store data on a streaming tape device like a DAT drive, or store files in what is commonly called a tarball file- somewhat like a pkzip file, only compression is optional.

howto / tar-gzip
site: http://www.fluidthoughts.com/howto/tar-gzip/
Unix file compression utilities

Tar Notes
site: http://www.bic.mni.mcgill.ca/users/kate/Howto/tar_notes.html
tar stands for tape archive and can be used to make a big file filled with many smaller files which can then be easily transported across directories, mahcines or networks. Cool, huh?

Howto untar a tar file or gzip-bz2 tar file
site: http://howto.wikia.com/wiki/Howto_untar_a_tar_file_or_gzip-bz2_tar_file
Tar file can come compressed or uncompressed. Generally that are compressed using gzip or bzip2. The program, tar, will uncompress both types and extract the files from archive.