Data Access Objects are the main classes where you define your database interactions. They can include a variety of query methods.

The class marked with @Dao should either be an interface or an abstract class. At compile time, Room will

generate an implementation of this class when it is referenced by a Database.

An abstract @Dao class can optionally have a constructor that takes a Database as its only parameter.

It is recommended to have only one Dao class in your codebase for all tables.