Membranes swept?

What does this mean? That they break your water? Wouldn't that be a risky situation though? I thought, although I may be mistaken, that 24-48 hours after your water breaks if you haven't had the baby yet you're at a greater risk of infection. Am I wrong? It's a little confusing to me as I was induced with both my boys so when my water was broken it was just part of the process during labour.