What is the belay device called?

A commonly used belay device is called an "ATC" (Air Traffic Controller), which is a tube-style device that allows for effective rope management and control while belaying a climber. Another popular type is the "GriGri," a self-locking device that provides additional safety by automatically locking the rope in case of a fall. Both devices are essential tools for climbers to ensure safety during ascents and descents.