Why do we have to do this inorder to read apps and open apps?

Question

i have no clue what to do just need java for phone to work?

Answer 1

JavaScript is not Java. If you're trying to get into Android programming Java is a good start, but there will still be a lot to learn. Once you make it through the course here and feel you understand it try checking out https://developer.android.com/studio/index.html and following the basic tutorials until you understand those, then move on to trying to do your own things. It would also be a good idea to work on reading documentation as Java and Android both use a similar style, as so many other languages.