GE dishwasher doors lock automatically when the wash cycle is started, preventing the doors from being accidentally opened. The water temperatures are too hot to be safe. When the cycle is complete and the digital timer or the rotary dial show that the machine is off, the door is unlocked.
Some GE dishwashers also have a safety lock. This keeps children from opening the door and using the dishwasher on their own. The lock must be released, usually by the lock key on keypad models. The rotary dial models, which are operated by turning a dial to the preferred wash cycle, usually don't have this feature.