Many people use the terms “pilchard” and “sardine” interchangeably. However, there is a difference between the two. In some cases, the terms may refer to the size of the fish. The larger fish are pilchards, and the smaller fish are called sardines. In some parts of the world, the terms “pilchard” and “sardine” may describe the same fish species. However, in other regions, such as the United States, “sardine” refers to the European pilchard.