Okay kiddo, imagine you have a can of paint and a paintbrush. When you want to paint something, you dip your paintbrush into the can of paint and then use it to paint what you want.
Well, people who want to attack a computer use something called "jit spraying." Instead of using paint, they use little pieces of code (like letters and numbers) to try and sneak into a computer's memory.
When the bad guys use jit spraying, they first find a weakness in a computer program. Then they figure out what kind of code they can sneak in to take advantage of the weakness.
The bad guys send this sneaky code to the computer all at once, like spraying a bunch of paint at once. This is called "jit spraying." The computer then has to try and figure out what to do with all the code that was sprayed at it.
Sometimes the computer gets overwhelmed and can't handle all the code, which can lead to the bad guys taking control of the computer.
But don't worry, kiddo, there are people called "cybersecurity experts" who work hard to find and fix these weaknesses before the bad guys can use jit spraying or other ways to sneak in.