Is it so hard to use Google. Just search "bitcoin faucet wiki" and you will find answer. And I don't know what "how to program it" means? If you are talking about automated bot to claim from faucets, you won't find it. Even if some fraudsters have it, they never share it public.
Just an online site that gives a few cents of Bitcoin to kick start those wanting to invest in Bitcoin without buying or mining them.
Let me correct you - bitcoin faucet don't give few cents, it give part of cents, something like $0.001.