Fire stopping, also known as compartmentation, is a fundamental part of fireproofing. Any opening between compartments around their entry and exit points allow fire to spread. Pipes and cables create some gap which pass through walls and ceilings.
Fire sleeves or Fire stops seal that gap and in the event of fire they expand rapidly and seal the gap.
Fire-resistant material is used to fill the joints and openings between walls and floors. This prevents fire from spreading between compartments in a building. This also prevents smoke and toxic gases from entering to other parts of the building.