Sometimes you would need to extract or create an archive file (i.e to install a script, you would usually download an archive and extract it to continue the installation). The very first step in the process would be to identify the exact archive type by looking at the file extension. The most common archive types are zip (ending with .zip), tar (.tar), Tar+Gunzip (.tar.gz), Bzip (.bz2) and Rar (.rar).
Each archive type has its own command for compressing/extracting as listed below.
To extract a ZIP file, please use:
unzip archive.zip
To extract a Tar file, please use:
tar -xvf archive.tar
To extract a Tar.Gz file, please use:
tar -zxvf archive.tar.gz
To extract a Rar file, please use:
rar x archive.rar
Each archive type has its own mechanism to create a new archive file. The most commonly used however is the tar.gz format. An example of creating such a file can be seen below:
tar -zcf archive-name.tar.gz foldername/
Source: http://www.siteground.com/tutorials/ssh/ssh_extracting.htm