Will someone explain trolling to me?

[Nineran]

So you have a thread going. Its progressing along, people are making constructive comments, all good.

Then someone makes some really nonsensical post. You assume its a "troll".

What do you do to avoid being "trolled".

You know its a troll. But you don't want this nonsensical comment to just go by as if its a useful addition to the thread, you need to respond and defeat it. But then if you do, you are getting trolled and somehow you lost at the internet ( I think there is a z at the end of that?)

Or you can leave it. Ignore this (troll) Its like leaving a turd on your front pathway, that you don't even try to clean up with a retort. So maybe then you win at the internet (z) but you have a turd sitting on your front porch.

So I don't quite understand who wins and who loses when there is a troll running rampant. Who judges these interactions? And why do I feel like I won at the internet (z) when I respond condemning said troll and kicking him back into his pit.