While the concept of optional types, as used in the Swift language, might seem a little foreign at first, the more you use them the more they will make sense. One of the biggest advantages with optional types is we get additional compile time checks that alert us if we forget to initialize non-optionals prior to using them.
These two paragraphs give examples of what optionals actually are and how they are defined in Swift. It is import to understand this concept because optionals are used a lot in Swift.
In the next chapter we will be looking at Generics in Swift.