Trolling forums?

I watched the video and it showed the word 'trolling forums' as asking hobbies.
I looked up the word in the dictionary but the explanation is hard for me to understand especially in the context.
I think it is kind of a buzz word if my guess is right.

Can anyone explain about trolling forums with easy and simple explanation?

Thank you in advance!

This existing thread will help you. 👁 Smile :)

he's trolling people

Thank you!