So, what is meant by paradigm?

Programming paradigms are ways, or styles, of programming. They are not specific languages; they are not coding templates; they are alternative approaches to dealing with the task of turning ideas into code. The borders between one paradigm and another are often blurred, and many languages support or enable programming in more than one paradigm. Even the programming-theory experts can't always agree on which paradigms are a subset of some other.

We're not going to get too pedantic here, but we will divide programming into two broad categories, imperative and declarative, both of which are directly relevant to programming in Swift.