Biology is defined as the study of living organisms, divided into many specialized fields that cover their morphology, physiology, anatomy, behavior, origin, and distribution.
Biologists are often times a very generalized field as there are many sub-subsections. For example you can be a biologist that specializes in canines or felines or any other variety of animals.
Biologists can work in the lab or in the field. Field work generally involves going into areas and studying your specialty in the wild.