What does "unsupervised weekends" mean?

WE have been told that we are probably going to start 'unsupervised weekends' after our next court date (in about a month). This is a good thing, our kids bio mom is busting her butt and doing everything right, and the kids miss her. I am not upset about the progress to unsupervised weekend visits, Im just not real clear on what exactly that means. With the understanding that everything is a little different everywhere, what is your experience with this? Are we likely to be talking about all day on Saturday, or will we just start off Friday afternoon to Sunday evening from the very fist visit? I am like our 3 year old, we both do much better when we know what is going to happen!