Teaching assistants (TAs) are students who assist professors with teaching duties. Teaching fellows (TFs) are students who receive assignments to take full responsibility for teaching lower-level courses.
At the beginning of the fall and spring semesters, the Toulouse Graduate School holds an orientation for all new teaching assistants and fellows. The TA/TF Orientation instructs new TAs and TFs in university policies that affect their employment and provides training pertinent to teaching and classroom management. Some departments hold additional orientations prior to the start of the semester.
For further information, here are some references you will find useful: