Popular Forum Scripting Technique

I am currently scripting a forum and need some help with a technique I have seen on other forums.

I have seen this on some forums, where they only show say 10 threads per page but I have know idea how they do it?

The threads for my forum are stored in a database.

Does anyone know this technique or could explain to me how it works?

Thanks.

if you're using asp.net - it's with datagrids... I read about it in my book... i could copy it later for you.