Earlier in this book, we talked about concurrency patterns and a bit about workers. We even brought the workers concept into play in the previous chapter, when we were building our logging systems.

Truly speaking, "worker" is a fairly generic and ambiguous concept, not just in Go, but in general programming and development. In some languages, it's an object/instantiated class, and in others it's a concurrent actor. In functional programming languages, worker is a graduated function return passed to another.

If we go back to the preface, we will see that we have literally used the Go gopher as an example of a worker. In short, a worker is something more complex than a single function call or programmatic action that will perform a task one or more times.

So why are we talking about it now? When we build our channels, we are creating a mechanism to do work. When we have a struct or an interface, we're combining methods and values at a single place, and then doing work using that...