What does "unsupervised weekends" mean?

Here we started with unsupervised all days( 9 am to 7pm) On the weekends, this was for 5 all day visits. This weekend will start the first over night. He has been approved for Friday night to Sunday night . Dad will proberly have 3 all night weekends before the boys go home around the end of this month. This tranistion has taken about a month and half and was mainly longer because one of the boys is 20 months old. Both boys have been in care for 1 yr.