Dumb question but....what's a "Troll"?

gmedlock

I've lurked on other boards and have noticed ppl calling others Trolls and saying they are lying about being pregnant/having kids/pictures are fake.

What exactly is that? Do they mean that someone has pretended to be all those things and copy others pics? If so, WHY??

I'm new to the internet forum/social scene so forgive me if I sound too stupid.

Definately glad I'm in Jan 2012 moms board! It's the most sane of the boards I looked at!!!!