This chapter discusses the historical perspectives of biotechnology and explains the classifications of biotechnology based on its applications. It explores how biotechnology has revolutionized the healthcare, agricultural, and environmental sectors and outlines how biotechnology became the science of integration of diverse fields. The chapter considers the rule of ethical issues on biotechnology. In general, biotechnology is a field that uses biological systems or living organisms to manufacture products or develop processes that ultimately benefit humans. Animal biotechnology is the application of scientific and engineering principles to the processing or production of materials from animals or aquatic species to provide research models and to make healthy products. Industrial biotechnology is known mainly in Europe as white biotechnology. It is the application of biotechnology for industrial purposes such as manufacturing of biomolecules, enzymes or chemicals, and bio-materials. In addition to the major fields of biotechnology, some other fields are directly or indirectly associated with biotechnology.