The Black-Scholes option pricing formula is a 1997 Nobel Prize winning result in economics (& mathematical finance) that provides a framework for rational pricing of a large class of stock options. In this talk we will discuss the basic idea of an option on an asset as well as the problem of fair valuation of such a financial object. Then, assuming that the stock price S_t follows a geometric Brownian motion, we will discuss a rough hedging argument that results in the Black-Scholes partial differential equation as a necessary condition for risk-free portfolio evolution. Using changes of coordinate systems and integrating factors, the Black-Scholes partial differential equation will be transformed into the classic heat (or diffusion) equation, for which a standard integral solution form is known. Finally, we will use this integral solution to derive the celebrated Black-Scholes option pricing formula. Some limitations of this model will also be discussed.