What is the difference between research assistantship and teaching assistantship?
At my university, RAs are paid for 20 hours of nominal work a week, usually through grant funds, to work on a research proejct. TAs are paid for 10 hours per week per course with departmental or university funds to assist the professor of a course. Their duties may include: teaching so-called recitation sections of the course where the week's lecture materials might be reviewed or homework questions discussed or clarified, holding office hours where students can come to ask questions about material they do not understand or get guidance on homework, and marking homework problem sets. TAships generally do not involve doing research with a prof, though students with a TAship may transition to an RA with a professor if they sufficiently impress one during their TAship. The level of pay and benefits is the same (per hour) at my university. Both TAs and RAs are generally restricted to 20 hour per week of nominal work, and health insurance benefits don't kick in until they reach that level.