Concealed door closers fall into two types: concealed in the door, or concealed in the floor.
Door Concealed, or Chain Closer:
The door concealed type usually has a chain connecting it to the door frame, and is very popular due to the simple and economical design. However, due to the size restriction, the weight capacity, speed control and reliability is likely to be less than the traditional overhead closer.
Floor Concealed Closer:
These are high-performance closers with the benefits of an overhead closer but concealed in the floor. They connect to the door via a sturdy pivot, and are available in single action (for doors that open in one direction) or double action (for doors that open inwards and outwards).