There are 2 types of assignments in Peergrade; Live Sessions and Regular Assignments. One main difference is Live Sessions are outside of classes and assignments are made inside of classes.
Live Sessions do not have deadlines and students immediately move into giving feedback as soon as they have submitted.
Assignments have deadlines for submission and feedback. The submission and feedback cannot overlap in Regular Assignments. Assignments also has a few extra features that aren't yet available in Live Sessions like group submissions and categories.