Type at the command prompt
tar xvzf file-1.0.tar.gz - for uncompress a gzip tar file (.tgz or .tar.gz)
tar xvjf file-1.0.tar.bz2 - for uncompress a bzip2 tar file (.tbz or .tar.bz2)
tar xvf file-1.0.tar - for uncompressed tar file (.tar)
x = eXtract, this indicated an extraction ( c = create to create ) v = verbose (optional) the files with relative locations will be displayed. z = gzip-ped; j = bzip2-zipped f = from/to file ... (what is next after the f is the archive file) The files will be extracted in the current folder (most of the times in a folder with the name 'file-1.0').