If you could look inside a pressure cooker when it's boiling at full pressure and high temperature, the boiling would appear different from ordinary boiling at atmospheric pressure (1 ATM).
In a pressure cooker, the boiling point of water is elevated due to the increased pressure inside the sealed pot. Typically, a modern pressure cooker operates at a pressure of around 15 pounds per square inch (psi) or 1 bar, which corresponds to a temperature of approximately 121-122 degrees Celsius (250-252 degrees Fahrenheit). At this higher pressure, water boils at a higher temperature compared to its boiling point at 1 ATM, which is 100 degrees Celsius (212 degrees Fahrenheit).
The boiling process in a pressure cooker is more vigorous and intense compared to ordinary boiling at atmospheric pressure. The boiling liquid inside a pressure cooker tends to release steam in short bursts rather than the continuous bubbling observed in a regular pot. The steam is generated as the liquid reaches its elevated boiling point and rapidly converts to vapor due to the high pressure.
If you could observe inside the pressure cooker, you would see the liquid rapidly boiling and releasing intermittent bursts of steam. This unique boiling behavior is a result of the higher pressure and temperature conditions within the sealed environment of the pressure cooker.