Explain Shell is a free online service that will break down command line arguments that you enter for you. If you do not know what the commands find . -type f -print0, tar xzvf archive.tar.gz or iptables -A INPUT -i eth0 -s ip-to-block -j DROP do, you can find out now using the service.

Full article here:
Explain Shell breaks down Linux command line arguments for you (gHacks)