Imagine you have a box full of different toys. When you want to play with a toy, you usually take it out of the box, play with it, and put it back before taking out another toy to play with. This is similar to how our computer works.

Now, let's say you have a special toy that can make sounds. When you press a button on it, it starts playing music. Usually, when you press the button, you have to wait until the music finishes playing before you can do anything else. This is like a blocking I/O call.

But with non-blocking I/O calls, it's different. Let's imagine that instead of waiting for the music to finish, you press the button, and while the music is playing, you can still play with other toys! You can even press buttons on other toys and play with them at the same time. The music is playing in the background, but you can do other things without waiting for it to finish. That's what non-blocking I/O calls do on a computer.

In simple terms, it means that the computer can do multiple things at the same time without having to wait for each thing to finish before moving on to the next thing. It can handle different tasks simultaneously, making it faster and more efficient.