Tannins?

[tandkvd]

As I am learning more about wines. I keep comming accross the refference of tannins. Could someone inform me as to what tannins are, in laymens terms?

I was informed at a wine shop that wines such as Merlots are produced aroud the tannins. And wines such as Pinot Noir are produced around.... I can't exactly recall the term he used.

I guess I just didn't want to admit to him that I did not know what the heck he was talking about.