How to extract gz, tar.gz and .tgz file?

How do I extract a gz file?

Use guzip command as follows:
$ gunzip file.gz
$ gzip -d file.gz
To see new file, enter:
$ ls -l

How do I extract a tar.gz or .tgz file?

Files with extension tar.gz or .tgz are tar files compressed with gzip. On Unix system extract them with following command:
$ gunzip < file.tar.gz | tar xvf -
$ gunzip < file.tgz | tar xvf -

If you have GNU tar (Linux system) you can use the z option directly:
$ tar xvzf file.tar.gz
$ tar xvzf file.tgz