Butler's purpose is to make it easier for you to perform different --- potentially recurring --- tasks. Butler lets you arrange these tasks in its fully customizable configuration. There, you can assign one or more triggers to a task.
Due to its unique variety of triggers and tasks, Butler is more flexible than any other utility you've seen before. So don't worry if you don't have a use for all of its features right from the beginning. Just start using Butler and discover a new feature every day.