What happens to old Threads?

[Grinnygog]

I'm sorry to ask such a general question that's probably answered SOMEWHERE on this site, this thread can be deleted when answered. When I first started using this site, there were some threads that no longer appear. It's always been just 2 pages of threads. Is that the limit? What happens to the older threads? Are they archived somewhere? There were threads "Running Through The Garden" and "Smile At You". Did they fall off because discussion stopped on them?

Once again I'm sorry for asking a general question here, but being new and trying to expand my Stevie knowledge as much as possible I'm interested in older posts.

Thanks.