The optimal transport problem asks: What is the cheapest way to transport goods (e.g. bread in bakeries) to desired locations (e.g. grocery stores)? Although simple to state, this problem is tricky to solve. Optimal transport is closely related to a nonlinear PDE called the Monge-Ampere equation, and important questions about optimal transport can be approached using this connection. In this talk we will discuss optimal transport, its connection to the Monge-Ampere equation, and some recent applications of optimal transport theory in geometric and functional inequalities and meteorology.