Resources are the additional static content and files that are an intrinsic part of your application but aren’t part of your Java code. Resources can take these forms:
Earlier chapters in this book introduce you to layouts, strings, and images because they’re the most common types of resources that you use in everyday Android application development. The remaining resources may be muddy, so the following few sections clear them up.
In an Android resource, a dimension is a number followed by a unit ...