SOA Architecture

Service-Oriented Architecture (SOA) is a design model that makes software components reusable through service interfaces that share a common language to communicate over a network.

A service is a self-contained unit of software functionality (or a set of features) designed to perform a specific task such as fetching information or executing an operation. It bundles the code and data integrations needed to deliver a complete, distinct business function.

It can be accessed remotely, and updated or interacted with independently. In other words, SOA lets software components that are deployed and managed separately communicate and work together to form software applications shared across different systems.
Source: redhat