A fellow is a concept whose exact meaning depends on context. In learned or professional societies, it refers to a privileged member who is specially elected in recognition of their work and achievements. Within the context of higher educational institutions, a fellow can be a member of a highly ranked group of teachers at a particular college or university or a member of the governing body in some universities; it can also be a specially selected postgraduate student who has been appointed to a post (called a fellowship) granting a stipend, research facilities and other privileges for a fixed period (usually one year or more) in order to undertake some advanced study or research, often in return for teaching services. In the context of research and development-intensive large companies or corporations, the title "fellow" is sometimes given to a small number of senior scientists and engineers. In the context of medical education in North America, a fellow is a physician who is undergoing a supervised, sub-specialty medical training (fellowship) after having completed a specialty training program (residency).