Service-oriented architecture (SOA)

SOA is another application architectural style. In SOA, architecture services are provided to other services and to vendor components using a communication protocol over a network. These services are discrete units of functionalities that can be accessed remotely. The following diagram shows an SOA in action:

As you can see in the preceding diagram, there are two main layers of the SOA: a service consumer layer and a service provider layer. The service consumer layer is the point at which all the consumers, such as human consumers and other service consumers, interact with the SOA. The provider layer is the point where all services are defined within the SOA.

In the preceding diagram, the Enterprise Service Bus (ESB) provides communication by a common communication protocol, or communication bus, which has connections between the consumers and providers. In SOA architecture, database storage is shared between all services.

SOA has more dependent ESBs. The ESBs implement a communication system between mutually interacting software applications with microservices. It also uses faster messaging mechanisms.

Let's now move on and take a look at the differences between SOA and microservice architecture.