Fellowships provided by federal government agencies or private organizations can often be used at more than one institution and are called portable graduate fellowships or external fellowships. This type of fellowship allows you to choose the best program for your goals, rather than being stuck with the only graduate program you can afford. There are also fellowships offered by universities to students in the school's graduate programs. Fellowships are often given to one field of study or other student demographic.
Some graduate students receive general assistantships that fulfill administrative or academic roles. These roles may be in the administrative offices of the university, or the student may perform duties related to academia that are not teaching, such as grading. These assistantships may be offered by the student's department but also can be found in other areas of the institution.
A graduate teaching assistant helps in the teaching of academic courses or is responsible for teaching a certain number of courses. A teaching assistant may also be assigned to a professor to help with academic duties such as grading or preparation for classes that are not necessarily teaching. Generally, a certain number of graduate credit hours are required before a teaching assistant can instruct a course.
When a graduate student receives a research assistantship, the student works under the supervision of a professor or researcher on a particular project. These assistantships are offered by the department the student is enrolled in or by the professor conducting the research.