The term "dorsal side" refers to the back or upper surface of an organism. In animals, this is typically the side that faces away from the ground when they are in a natural position. For example, in humans, the dorsal side corresponds to the back, while in fish, it refers to the top side of the body, often where the dorsal fin is located. In anatomy, the dorsal side is contrasted with the ventral side, which is the front or belly area. This distinction is important in various fields, including biology and medicine, as it helps in describing the location of structures and understanding the anatomy of different species, such as mammals and reptiles.