IN THIS CHAPTER, WE’LL EXPLORE THE MEANING OF THE TERM “SERVICE” AND ITS ASSOCIATED concepts (such as interfaces and contracts).
As for SOA, there are multiple definitions of the term “service.” For this reason, I will again quote definitions from various existing sources, such as the OASIS SOA Reference Model, Wikipedia.org, and some books. I will then present my personal definition of the term.
To get a complete picture of what services are, you’ll have to read further in this book. The goal of this chapter is to provide a general definition that will serve as a base for later discussions in this book.
The OASIS SOA Reference Model [OasisSoaRM06] states:
The noun “service” is defined in dictionaries as “The performance of work (a function) by one for another.”
This can mean everything or nothing. As with the term SOA, it is hard to find an exact, useful definition of the term “service” because so many definitions exist. Again, I have collected some of these definitions and put extracts of them in sidebars throughout the chapter. You’ll find some common phrases and attributes as you read them, but you will also find a lot of differences in the context, level of abstraction, and wording. As in the previous chapter, I’ll begin by presenting my understanding of services.