I am a beginner, but I summarized it for personal study
You can change the appearance of the ** Project tool window **, which defaults to ** Android view ** In Android view, only the files necessary for development are displayed, and if necessary, switch to another view such as ** Project view **.
・ It is roughly divided into 3 folders: ** manifests **, ** java **, ** res **.
・ ** AndroidManifest.xml ** file is stored -The AndroidManifest.xml file describes ** settings required to run the app **.
-As the name suggests, the java file is stored. -(AndroidTest), (test) on the right side of the package is the storage location of the .Java file for testing the Android application.
-Stores .xml files and image files used in apps ・ The res folder has the following subfolders ① ** drawable ** ･ ･ ･ Stores images ② ** layout ** ･ ･ ･ Stores .xml file related to screen configuration ③ ** mipmap ** ･ ･ ･ Stores the app icon ④ ** values ** ･ ･ ･ Stores fixed character strings (String.xml), screen styles (styles.xml), and .xml files that represent color configurations (colors.xml) stored in the app.