Service Oriented Architecture (SOA) is a business-driven concept based on a style of architecture that uses loosely coupled services and components to support the requirements of business processes and users. It is evolutionary in terms of its distributed computing approach (software running on multiple platforms) and modular programming style.
The value of SOA is in its ability to create "building blocks" of functions or services that can be rapidly and cost-effectively connected into the existing business infrastructure. Previously, software programs were written as monolithic, closed, integrated programs. The addition of each new feature impacted the entire program, requiring a full program test for each program code update. SOA's distributed computing approach and modular programming style avoids this by creating "building blocks" of functions or services that can be connected.
