In this chapter, we will learn some fundamental concepts of the Groovy programming language. This chapter briefly covers Groovy data types, control structures, object oriented concepts, collections, closures, and builders. This is just the tip of the iceberg. As this is not a Groovy book, we won't be able to cover all the topics. This chapter is meant for beginners who are coming from a Java background and have a basic understanding of Object-oriented programming (OOP) concepts. This will help them get started with Groovy. This chapter will also act as a tool box to proceed with Gradle scripting.