I'm starting to study Android using the Android Studio tool and I have a problem: even though I search for books or video lessons I never find one that is up to date.
I have version 1.5.1, and when creating a project two XML files are created in the layout folder, one called content_main.xml and another called activity_main.xml
In places I see, it does not show the creation of the file content_main.xml . What is it for? Why did this change happen?
content_main refers to the content of your Activity, where you will edit the body of your Activity (put buttons, switches, etc.), and Activity_main is the layout itself, where you edit the widget and background (background) of your Activity
Note: I can not say that I am an expert on the subject (in fact I am very noob), but if you work with it, I recommend you to sand your java and also your xml, follow the updates and always read the functions and packages of android that you can use on their website link
La has everything you need practically to handle your app (like I said I'm not an expert), but if you're starting it's a good one
