How does 4chan work?

Can someone explain how these message boards work? I know it's anonymous. I'm curious as to how it manages content. Does it use a database but then delete it after a certain point? I'm just beginning to learn things like databases and server side programming but I've been curious as to how a website like 4chan actually works.

>>8
``lol im on 4chun and tink mootles~ is and overload here''
No, you aren't, kid. Here we've cough got MrVacBob-sama-kun.