Mobile development is when people create new apps or change already existing ones for phones or tablets. Think about your favorite games or the apps you use to learn something. For those to work on your phone or tablet, someone had to make sure that it works right on that device. That's where mobile development comes in.
Developers use special tools and programming languages to create an app. A programming language is like a secret code. The developers use this code to tell the app what to do when you click on a button or swipe the screen.
Before the app can be used, it has to go through a lot of testing. This means that people try out the app and look for any problems that need fixing. Once the app is done and everyone is happy with how it works, it gets sent to the app store.
When you open the app store on your phone or tablet, you can download your favorite apps or games. And that's how mobile development helps make your phone fun and useful!