Graduate Research Assistantships (GRA)
Graduate support that is provided by research funds obtained through grant writing by your advisor who is a PI or Co-PI on a project. The work you do may or may not be related to your graduate research/thesis. There may be annual or quarterly reports that all have firm deadlines so you need to work toward making significant progress on your research to satisfy the reporting requirements, discuss this with your advisor.
Graduate Teaching Assistantships (GTA)
Graduate support that is provided by the Graduate School through the department. The work you do supports departmental courses AND gives you experience at teaching.
This is often a full time commitment (up to 20 hrs/week on average) and the remainder of your work week is to be dedicated to your graduate research and scholarly activities.
The course instructor will outline the work to be done for the course. If you feel more than 20 hrs/week is being required please see your instructor and or the graduate advisor.