Graduate teaching assistants (often referred to as GTAs or simply TAs) are graduate students employed on a temporary contract by a department at a college or university in teaching-related responsibilities. In New Zealand, Australian, and some Canadian universities, graduate TAs are known as tutors. North American graduate TA positions provide funding for postgraduate research—although the main purpose is to provide teaching support—and it often serves as a first career step for aspiring academics.[3] TA responsibilities vary greatly and may include: tutoring; holding office hours; invigilating tests or exams; and assisting a professor with a large lecture class by teaching students in recitation, laboratory, or discussion sessions. Professors may also use their teaching assistants to help teach discussions during regular class. This gives the graduate student opportunity to use their teaching skills, as many are in pursuit of teaching careers. Some graduate students assist in distance education courses by meeting with the students as professors are not able to. Graduate TAs should not be confused with teaching fellows (TFs) or graduate student instructors (GSIs), who are graduate students who serve as the primary instructors for courses. However, at some universities, such as those in the Florida State University System, there are neither teaching fellows nor graduate student instructors, and "teaching assistant" is the only title used.
不是上课，所以不是TA
不是的。mentor还会在career上进行引导。这种就是老生带新生上手熟悉课题而已