A concealed cistern is a toilet water tank hidden behind the bathroom wall, allowing the toilet to sit flush against the wall. This design is popular in modern, minimalist bathrooms.
There are two types: one with a fixed frame for wall-hung toilets that supports the user's weight, and one for floor-fixed toilets. Both types function the same way when you flush them.
Concealed cisterns are often used in public restrooms in places like airports, restaurants, shopping malls, and offices. Recently, they have become popular in modern homes as well.