Event handler

An event handler is a bit like a helper that listens for things happening and then does something in response. It's a bit like having a robot friend who stands in your room and waits to hear a specific sound, like a bell ringing or a dog barking. When the robot hears the sound, it knows what to do next, like play a happy tune or turn on a light.

In computers, events are things that happen when you do something, like clicking a button or typing on the keyboard. An event handler is a special piece of code that listens for these events and then does something specific in response. So when you click a button, the event handler for that button knows what to do next, like change the color of a box on the screen or display a message.

Think of it like this: your computer is like a giant toy box full of all sorts of toys, and the event handler is the toy sorter that helps you find the perfect toy for any occasion. So if you want to play with a ball, the toy sorter knows exactly where to find it and brings it to you. And if you want to play with a puzzle, the toy sorter makes sure all the pieces are there and ready to go.

Overall, an event handler is just a fancy term for something that listens for things happening on your computer and takes action to respond. It's a bit like having a friendly helper who always knows what you need, even before you ask!