"A technology framework to support the design, development, and deployment of diverse business applications in a loosely coupled way. The goal of SOA is to encourage reuse of both data and functionality via the use of units of work (services) that are made available to different business processes across the enterprise." (Jill Dyché & Evan Levy, "Customer Data Integration", 2006)
"SOA is an architectural paradigm for dealing with business processes distributed over a large and heterogeneous landscape of existing and new systems that are under the control of different owners." (Nicolai M Josuttis, "SOA in Practice", 2007)
"An architectural style for creating an enterprise architecture that exploits the principles of service orientation to achieve a tighter relationship between the business and the information systems that support the business." (Tilak Mitra et al, "SOA Governance", 2008)
"A method for organizing a company's entire information system functions so all information components are viewed as services that are provided to the organization." (Jan L Harrington, "Relational Database Design and Implementation" 3rd Ed., 2009)
"A way of designing software applications for reusability and flexibility. It involves designing loosely coupled software components called services." (John Goodson & Robert A Steward, "The Data Access Handbook", 2009)
"An architectural style in which software systems are modular and some components (service providers) are distributable, discoverable, substitutable, and shareable." (W Roy Schulte & K Chandy, "Event Processing: Designing IT Systems for Agile Companies", 2009)
"An architecture that enables IT resources to be made available to other participants in a network as independent services that are accessed in a standardized way without knowledge of the underlying platform implementation." (David G Hill, "Data Protection: Governance, Risk Management, and Compliance", 2009)
"An IT infrastructure that allows disparate applications to exchange data and use consistent processes as they interact with each other. SOA is the foundation architecture for data services." (Tony Fisher, "The Data Asset", 2009)
"An architectural style to enable loosely coupled systems and promote re-usable services based on open standards." (Martin Oberhofer et al, "The Art of Enterprise Information Architecture", 2010)
"Defines a development paradigm which has loosely coupled, distributed modules called 'services' as its build blocks. Services offer clear interfaces through which service consumers can discover and make use of them." (Carlos Kamienski et al, "Managing the Future Internet: Services, Policies and Peers", 2010)
"In its most general sense, an approach for architectures where the interfaces are services. In a more specific sense, it is an architectural style for dealing with business processes distributed over a large and heterogeneous landscape of existing and new systems that are under the control of different owners." (David Lyle & John G Schmidt, "Lean Integration", 2010)
"The software design and implementation architecture of loosely coupled, coarse-grained, reusable services that can be integrated with each other through a wide variety of platform-independent service interfaces." (Alex Berson & Lawrence Dubov, "Master Data Management and Data Governance", 2010)
"An architectural concept that defines the use of services to support a variety of business needs. In SOA, existing IT assets (called services) are reused and reconnected rather than the more time consuming and costly reinvention of new systems." (Linda Volonino & Efraim Turban, "Information Technology for Management" 8th Ed, 2011)
"An application architecture in which all functions, or services, are created with invokable interfaces that are called to perform business processes." (Craig S Mullins, "Database Administration", 2012)
"An approach to building applications that implements business processes or services by using a set of loosely coupled black-box components orchestrated to deliver a well-defined level of service." (Marcia Kaufman et al, "Big Data For Dummies", 2013)
"A software design and software architecture design pattern independent of any vendor, product, or technology and based on discrete pieces of software providing application functionality as services to other applications. For instance, this software design defines how two computing entities, such as programs, interact in such a way as to enable one entity to perform a unit of work on behalf of another entity." (Jim Davis & Aiman Zeid, "Business Transformation: A Roadmap for Maximizing Organizational Insights", 2014)
"An information technology architecture that separates infrastructure, applications, and data into layers." (Robert F Smallwood, "Information Governance: Concepts, Strategies, and Best Practices", 2014)
"Style of architecture based on the concept of service, designed to simplify interactions between architecture blocks while providing the system with significant flexibility." (Gilbert Raymond & Philippe Desfray, "Modeling Enterprise Architecture with TOGAF", 2014)
"A design similar to a component-based architecture except the pieces are implemented as services." (Rod Stephens, "Beginning Software Engineering", 2015)
"Service-Oriented Architecture expresses an architecture that define the use of software services." (Laura C Rodriguez-Martinez et al, "Service-Oriented Computing Applications (SOCA) Development Methodologies: A Review of Agility-Rigor Balance", 2021)
"A multitier architecture relying on services that support computer-to-computer interaction over a network." (Oracle, "Oracle Database Concepts")
"Service-oriented architecture (SOA) is a design paradigm and discipline that helps IT meet business demands. Some organizations realize significant benefits using SOA including faster time to market, lower costs, better application consistency and increased agility. SOA reduces redundancy and increases usability, maintainability and value. This produces interoperable, modular systems that are easier to use and maintain." (Gartner)
"Service‑oriented architecture (SOA) is an architectural approach to designing applications around a collection of independent services. A service can be any business functionality that completes an action and provides a specific result, such as processing a customer order or compiling an inventory report." (NGINX) [source]