50 State Surveys are a compilation of the laws across jurisdictions (not always all 50 states) on a specific topic.
Example: Imagine being asked to compare the different laws regarding marijuana from state to state. Before searching through each state individually, look for a survey! Someone may have already done a lot of the legwork. The researcher still has to pull the actual statutes, read them, and update them, but a survey can save a tremendous amount of time.