Service Oriented Architecture
In plain terms
Structuring software as reusable, network-accessible services.
Going deeper
SOA composes applications from loosely-coupled services that communicate over a network, often via an enterprise service bus. It predates and influenced microservices.
Under the hood
Coarser-grained than microservices and often centralized via an ESB; emphasizes reuse and interoperability.
Examples
Enterprise integration, ESBs, reusable services, legacy SOA, web services.
Think of it like...
Like a company of specialized departments offering services to each other through a central switchboard.