A knee brace and / or knee bandage can be roughly divided into 3 types of protection / support.
The slightly supportive knee bandage (this is a more reinforced stocking).
The Medium support Knee Brace (support stocking with ribs). The Heavy protective Knee Brace with hinges (The "Hinged" version).
More protection is accompanied by more disability. Depending on what you want to be able to do in function and sport, In combination with the injury you have, the choice will be made.
A Knee Brace protects the bands / meniscii and cartilage in the knee
A knee bandage is mainly used to support and protect the knee bands. Knee bands can be damaged by trauma (rupture or partial rupture). A bandage for the knee then provides the necessary immobilization that is necessary to restore the bands.
A knee brace also ensures that the knee internal sliding movements in the knee are reduced. This has a beneficial effect on the structures in the knee that are sensitive to it.
You can think of menisci and the cartilage of the knee.