2. Pressure cooker, also known as pressure cooker and pressure cooker, is a kind of kitchen cooker. The pressure cooker makes the water reach a higher temperature without boiling through the physical phenomenon that the boiling point of liquid will rise under higher air pressure, thus accelerating the efficiency of stewing food. The principle of pressure cooker is very simple, because the boiling point of water is affected by air pressure, and the higher the air pressure, the higher the boiling point.