Same as the topic! 
Although there are many differences, I believe the most relevant difference is this: For both types of visa, part-time on-campus employment is allowed during periods of full study. The difference between the two arises during periods of recess. During periods of recess, students holding F1 status may work full time. Students holding J1 status may also work full time however, they will require the permission of their Alternate Responsible Officer.