Cladding. This is typically a non-structural decorative, insulated material. It goes on top of the concrete structure of the building. Various materials are used, plastics, aluminium, stone, various hybrid structures (e.g. brick tiles over polyurethane foam), etc.
There have been a number of major high-rise fires around the world which have been traced to cheap cladding material which did not meet code for fire resistance.
Yeah I always thought that the cladding would be aluminum or some other highly fire resistant material. That thing went up like a torch. Maybe it was the paint.