The observable universe is experimentally known to be extremely large, extremely old, and extremely complex. Nevertheless, the last 50 years has seen an enormous increase in our understanding of the origin and evolution of the universe – the study of which is the subject of an entire subfield of Physics and Astrophysics known as Cosmology. Much of what is currently known is consistent with a particular model known as the Big Bang. The purpose of this informal talk is to introduce the basic elements of this model and to describe the experimental evidence that has lead to its general acceptance.