A breed is a specific group of animals or plants having homogeneous appearance, behaviour and other characteristics that distinguishes it from other animals or plants of the same species, e.g. Red Dane, Jersey, Brown Swiss are some common breeds of cow.
Species is one of the basic units of biological classification and a taxonomic rank. It can be defined as the largest group of organisms capable of interbreeding and producing fertile offspring, e.g. lion, cow, dog.