No, ham can be made from any type of meat. The word "ham" comes from the Old English word for "thigh," and so it originally referred to the hind leg of an animal. Over the period, the term came to refer to any cured or smoked meat from that area of the animal. So, while pork is the most common type of ham, you can also find ham made from beef, lamb, chicken, and even fish. Each type of ham will have its own unique flavor, depending on the type of meat and the curing process used.