Multiple forums can be merged. It doesn’t just have to be two. It can be more than that. But, for the sake of this article, to keep it simple, we’ll speak as if it is two forums that are merging into one, since that is the most common scenario.
When two forums are merged, the two separate databases are consolidated into one, meaning all members, posts and content will now constitute a single forum. If one forum had 400,000 posts and another had 300,000 – there is now one forum with 700,000 posts.