What is a forum?

“A forum is a place, situation, or group in which people exchange ideas and discuss issues, …”—COBUILD

I wonder what they want to talk about.

The forum is not for exchanging Skype IDs but for exchanging ideas.

Then there is “Up Pompeii!”, classic British (Roman) comedy, based on Plautus’s plays from 2,000 (?) years ago, and the US musical from the 1960s “A funny thing happened on the way to the Forum”.