The method of hypergraph containers is a modern incarnation of a classical proof technique concerned with enumerating certain classes of graphs. Perhaps the origins of the method lie in a paper of Kleitman and Winston about enumerating the number of n-vertex graphs containing no 4-cycle. The full generality and power of this approach became evident only in the past decade when very general theorems were proved with wide applicability to a host of questions. These results are concerned with counting the number of independent sets in a hypergraph. Two essentially equivalent approaches were developed by Saxton and Thomason and by Balogh, Morris, and Samotij, and our goal is to state one of these results and give some applications.