ProfessorA professor is a teacher mostly in a college or university.
In Canada and the United States, the faculty of a college or university is organized hierarchically, ranging from teaching assistants, assistant professors, associate professors, to full professors. In most other English-speaking countries, equivalently senior academics to assistant professors and less-prestigious associate professors are generally known as "Lecturers" and "Senior Lecturers", with associate and full professorships reserved for only the most senior academic staff.
Professors give lectures in their field of study, such as science or literature. They also do advanced research in their fields. Many Nobel Prize laureates are professors. After a professor retires from active teaching duties, they often continue to appear on faculty listings, designated as professor emeritus.
In theory, professors are free to hold and advance controversial views, as the faculty generally insists on academic freedom. Full professors are usually awarded "tenure". Generally, a tenured professor cannot be sacked except in the case of gross misconduct.
In fiction, in accordance with a stereotype, professors are often depicted as being absent-minded. An obvious example is the 1961 movie The Absent-Minded Professor.