What is medical detox like at a facility?

Has anyone been to medical detox at a facility? They have a detox program that I am looking into for Heroin & after that they have what is called a transitional program that you go to before you go to 30 day treatment. She couldn’t get explain transitions to me but I read online that the length varies depending on the person & I think it is just a matter of days from what I read. Anyway, what happens at a medical detox place? Do they have like groups & classes? I know I can have my phone in detox but not in rehab. That is all I know though. If anyone has been please tell me your experience. Or if you have been to detox at a hospital tell me how it was. I have another friend who went to the hospital for 3 days. He said his wife stayed with him there in the room & he was started on an IV as soon as he got there & he was given Ativan & Suboxone. Anyway, any information would be greatly appreciated. Thanks in advance!