In this talk, we will describe the only millennium problem solved so far: Poincare Conjecture. We will talk about the background of the problem, and give an overview of Perelman's solution via Ricci Flow. In particular, without going into technical details, we will describe the Thurston's Geometrization Conjecture which gives the complete classification of 3-manifolds.

The talk is targeted for general audience; undergrad and grad students are encouraged to attend.