Okay kiddo, a krytron is a special device that helps to control very high voltage electricity. It's like a switch that turns on and off a really strong electrical current.
Imagine you have a huge bucket of water, but you need to keep the water from spilling out until you are ready to pour it. A krytron is like a special lid for that bucket that you can open and close when you want to pour the water out.
But instead of water, a krytron controls electricity. It has a special gas inside of it that gets ionized when a high voltage is applied. This ionization allows the krytron to conduct electricity, meaning that it lets the electricity flow through it.
When you want to turn off the high voltage electricity, you use a trigger signal to stop the ionization process, and the krytron stops conducting electricity.
Overall, a krytron is like a special switch that can handle very strong electrical currents, which can be useful in things like particle accelerators or other high-energy technologies.