Android 10 is a version of the mobile operating system (OS) and it is the 10th major release and it's also the 17th version of Android. Which was the latest Android version installed in mobile devices until the Android 11 version was introduced back in September 2020. This version of Android hosts many advancements, and technological updates that are being tweaked every time, to enhance Android’s capabilities and extend its features. What you will find in many mobile devices would be customized Android 10, which is a customized version of Stock Android that Google developed.
If you wish to become an Android App developer, I would highly recommend you to become one, by enrolling in the Android App development course from Intellipaat. Which is a package of 16hrs of training and 32hrs of project-work and exercises. And also watch our YouTube video on Android Application Tutorial.