As we mentioned in the first chapter, this book is not an introduction to object-oriented programming (OOP). If you've read this far, we assume that you are already familiar with OOP and understand the concept of classes. Classes exist in Apex just like in other languages. There are, however, some differences between how classes are written in Apex and in other languages and this is what we will focus on in this chapter.

The majority of Apex code that you will write will be in a class; however, Apex also includes triggers. While you might be familiar with the concept of triggers already, Apex triggers are unique to the Salesforce1 Platform, so we will explain everything you need to know to start writing them.