In the strictest sense, "Biotechnology" is "the use of cellular and molecular processes to solve problems or make products," and biotechnology firms use cells and biological molecules for applications in medicine, agriculture and environmental management. From this definition, pharmaceutical companies (except for those with distinct biotechnology divisions), contract research organizations and euipment manufacturers are not considered biotech firms.
More broadly, "Life Sciences" firms include those that design and produce medical devices and instruments and pharmaceutical companies, and in some cases may include medical labs, hospitals, and medical centers.
"Biosciences," the broadest of the defined terms, incorporates all of the above as well as agricultural chemicals and research and testing.
Source: New York Biotech Report, Prepared by Insignia/ESG, Inc.