What is a service?

SOA is about services. So, let us start there. What is a service? Informally, and in the broadest sense of the word, a service is something useful a provider does for a consumer. Products can be considered a service too. Services can be paid for since the producer has created added value during their production. A service can be something tangible like a carton of milk, a car, a new house but also something intangible such as travel insurance or medical treatment. Services can be simple like fixing a bike. However, there are also more complex services such as purchasing a new smartphone together with a flexible phone plan including 300 free text messages a month, and the accompanying advice from a provider's sales representative. These more complex services are thus composed of various other services.

In short, a service is an economic term to describe the goods and services that organizations and people produce, sell to one another, and buy from each other. Services...