Okay, kiddo, so you know how sometimes grownups go to work to make money and do important things? Well, there are certain rules that say how old you have to be before you can go to work too.
The legal working age, which is like a rulebook for when it's okay for kids to get jobs, is different in different countries. In some places, you have to be at least 14 years old to work, while in others you might have to wait until you're 16.
Now, just because you're old enough to work doesn't mean you can do any job you want. Jobs that are too hard, too dangerous, or involve things you're not old enough to handle aren't allowed for kids. For example, you can't work in a factory or do construction work until you're older and stronger.
It's also important to know that even if you're allowed to work, you still have to go to school and do your homework. Going to school is important because it helps you learn and get better jobs when you're older. So you might only be able to work a few hours a day or on weekends so you can still have time for school and playing with your friends.
So that's the legal working age. It's a set of rules that tell us when kids are old enough to work and what kind of work they can do. But don't worry too much about it, kiddo - you've got plenty of time before you'll need to worry about a job.