What are semaphores?

A semaphore is like a special kind of sign that helps people take turns using something important.

Imagine you're at a playground, and there's only one swing left. You want to use it, but so do your friends. A semaphore acts like a little flag: if the flag is up, it means someone is already on the swing and you have to wait. When they're done, they lower the flag, and now it's your turn!

Think of the semaphore as a kind of "go" or "wait" sign:

• When the flag is up (1), it means someone is using the swing, you have to wait.
• When the flag is down (0), it means no one is using the swing, you can go ahead and use it!

This way, everyone gets a fair turn without fighting over the swing. It’s like having a friendly rule that makes sharing easier.

Sometimes, there are more than just one swing, maybe even five! Then the semaphore can act like a counter: if three friends are using swings, it shows 3, and when they're done, it goes down to 0 so others can join in!

That’s how semaphores help people share things politely and fairly.