Unique identifier

A unique identifier is like a name tag that is special to only one thing. Remember how you have a name and that makes you different from everyone else? It's the same thing with objects, but instead of calling it a name, we use something called a unique identifier.

Let’s say you have a toy car that looks exactly like your friend’s toy car. But your toy car has a special number on it that is just for your toy car. This number is your toy car’s unique identifier. No other toy car in the world has that exact same number. So even though your toy car looks similar to your friend’s, they are actually different because they have unique identifiers that are special only to them.

This number helps us identify things and keep track of them. For example, if you go to a store and buy a toy, the store may use a unique identifier to tell them that they sold that specific toy and not another one. They can also use it to see when they need to order more toys that look like it.

So, just like your name makes you unique, a unique identifier makes objects unique, too!