Three pirushim: 1. Tziun HaDeah – Mekoros for the Shulchan Oruch from the Beis Yosef (since the Beer HaGola is sometimes not complete). 2. Meir HaDeah – a synopsis of the Nosei Ceilim of the Shulchan Oruch. 3. Biur HaDeah – nowaday poskim.
It would be useful for beginners to study it instead of Shulchan Oruch, and advanced to study it as an introduction to Shulchan Oruch, and even more for Hazara, and for Rabbanim as a place to check if they forgot something.