1). "tar -zxvf file_name.tar.gz" -> This Command will decompress the files that have been tar'd and zipped using "tar" and "gzip" commands. as told earlier "tar" command used in command doesnt really compress or decompress, even here, "-zxvf" parameter tells, the program to compress or decompress:-
z -> compress or decompress "automatically". x -> "extract" the file. v -> display the "verbose" output to the end user. f -> with your defined "filename".
See example below
tar -zxvf w3box.tar.gz
This command will extract the file to root directory (/).
2). "gunzip file_name.tar.gz" -> This commands decompress those files which was compressed with gzip command.
3). "bunzip2 file_name.bz2" -> This commands decompress those files that have been compressed with "bzip2" command
4). unzip file_name.zip -> We all must be knowing ".zip" extension, So, this command decompress ".zip" files which have been compressed with "PKZIP" command for the DOS or Microsoft Disk Operating system.