Service - The named standard, unique, or proprietary packet structure and associated communication configuration that is instantiated on a port or range of ports. Common examples of services are: DNS, FTP and HTTP. For details see the Ports, Protocols, and Services Assurance Categories Assignments List. E2.1.18.
Service - Honorable active duty (including attendance at the military academies), membership in Reserve Officers' Training Corps Scholarship Program, Army, and Air Force National Guard, Military Reserve Force (including active status and ready reserve), civilian employment in Government service, or civilian employment with a Department of Defense contractor or as a consultant involving access under the Department of Defense Industrial Security Program. Continuity of service is maintained with change from one status to another as long as there is no single break in service greater than 12 months.
FSAM Glossary 1.1
Service - Discrete unit of functionality that can be requested (provided a set of preconditions is met), performs one or more operations (typically applying business rules and accessing a database), and returns a set of results to the requester. Completion of a service always leaves business and data integrity intact. (source: Federal CIO Council Services and Components Based Architectures Whitepaper)
Service - Refers to customer or product-related business functions such as file transfer protocol (FTP), hypertext transfer protocol (HTTP), and mainframe supervisor calls. Each system provides a set of services. For example, a computer network alls its users to send packets to specified destinations and a database system responds to queries.
NIST SP 800-123
Service - In the context of a server, a function that a server provides for other hosts to use.
NIST SP 800-95
Service - A software component participating in a service-oriented architecture that provides functionality or participates in realizing one or more capabilities. (Open Grid Services Architecture Glossary of Terms (25 January 2005), http://www.gridforum.org/documents/GFD.44.pdf)