Now that you’ve been introduced to the IR model and the accompanying query language in the last two chapters, you have a basis to delve deeper into the idea of implicit services. The concept of implicit services consists of a generic API that a client can use to access data on a server, without having to explicitly implement every possible request beforehand, as would be the case with service-oriented architectures (SOAs). At its core, an implicit service request is a set of queries. So, we could call it a query API. However, as you will see shortly, a generic service API goes much further than a typical database query API.