What can a realtor see with my Social Security number?

a realtor will need my Social Security number to run a credit check on me. im always weary about giving such personal information out, what can they actually see when they check this. because when i try to check my own credit, i really have to jump through hoops confirming my date or birth, family history, mothers maiden name, places ive lived the last 5 years, and so on, just a rigorousness hle of security questions. so can just a normal person like a realtor get all of that information just by knowing my SS number? or is the information he sees limited? thanks