A breed is a specfic group of animals or plants having homogenous appearance, behavour and other characteristiscs that distingusih if from other animals or plants of the same species ,e.g., Afghan shepherd,American bulldog are breeds of dog.
Species is one of the basic untis of biological classification and a taxononic rank , it can be defined as the largest group of organisms capable of interbreeding and producing fertille offspring e.g., loin , cow , dog are species.
