The /res subdirectories contain the resources for your application:
drawable-<density>/: Directories for drawable resources, other than launcher icons, designed for various densities.
layout: Directory for files that define your app's layout user interface
menu/: Directory for files that define your app's menu items.
mipmap/: Launcher icons reside in the mipmap/ folder rather than the drawable/ folders. This folder contains the image that appears when you run the default app.
values/: Directory for other XML files that contain a collection of resources, such as string and color definitions.