Really dumb question: Where does the data go?

I have read all the documentation, and dont understand this, When i click on submit is the html uploaded to the server? Can you do this? Am i being a complete idiot?

What my intention is, is to post lots of stuff to the server, and read them back like a message board sort of deal.

Forgive me for being a total burk but i don't have much experience in web design.