In this chapter, we introduced you to some of the most powerful types provided by the Swift language. Now that we know how to group various values, we can begin to think about how we can build the iOS applications that we have in mind. Before we get too ahead of ourselves, we need to talk about control flow. The next chapter will discuss working with collection types in detail. There are certain paths you will want to take in your code based upon certain conditions. 

For example, if the light is green, then we can go. If the light is red, then we should stop. These are certain conditions that dictate how we move forward. How we handle this in code is discussed in detail in the next chapter.