"A grid is an architecture for distributed computing and resource sharing. A grid system is composed of a heterogeneous collection of resources connected by local-area and/or wide-area networks (often the Internet). These individual resources are general and include compute servers, storage, application servers, information services, or even scientific instruments. Grids are often implemented in terms of Web services and integrated middleware components that provide a consistent interface to the grid. A grid is different from a cluster in that the resources in a grid are not controlled through a single point of administration; the grid middleware manages the system so control of resources on the grid and the policies governing use of the resources remain with the resource owners." (Beverly A Sanders, "Patterns for Parallel Programming", 2004)
"Clusters of cheap computers, perhaps distributed on a global basis, connected using even something as loosely connected as the Internet." (Gavin Powell, "Beginning Database Design", 2006)
"A step beyond distributed processing. Grid computing involves large numbers of networked computers, often geographically dispersed and possibly of different types and capabilities, that are harnessed together to solve a common problem." (Judith Hurwitz et al, "Service Oriented Architecture For Dummies" 2nd Ed., 2009)
"A web-based operation allowing companies to share computing resources on demand." (DAMA International, "The DAMA Dictionary of Data Management", 2011)
"The use of networks to harness the unused processing cycles of all computers in a given network to create powerful computing capabilities." (Linda Volonino & Efraim Turban, "Information Technology for Management" 8th Ed., 2011)
"A distributed set of computers that can be allocated dynamically and accessed remotely. A grid is distinguished from a cloud in that a grid may be supported by multiple organizations and is usually more heterogeneous and physically distributed." (Michael McCool et al, "Structured Parallel Programming", 2012)
"the use of multiple computing resources to leverage combined processing power. Usually associated with scientific applications." (Bill Holtsnider & Brian D Jaffe, "IT Manager's Handbook" 3rd Ed., 2012)
"A step beyond distributed processing, involving large numbers of networked computers (often geographically dispersed and possibly of different types and capabilities) that are harnessed to solve a common problem. A grid computing model can be used instead of virtualization in situations that require real time where latency is unacceptable." (Marcia Kaufman et al, "Big Data For Dummies", 2013)
"A named set of interconnected replication servers for propagating commands from an authorized server to the rest of the servers in the set." (IBM, "Informix Servers 12.1", 2014)
"A type of computing in which large computing tasks are distributed among multiple computers on a network." (Jim Davis & Aiman Zeid, "Business Transformation: A Roadmap for Maximizing Organizational Insights", 2014)
"Connecting many computer system locations, often via the cloud, working together for the same purpose." (Jason Williamson, "Getting a Big Data Job For Dummies", 2015)
"A computer network that enables distributed resource management and on-demand services." (Forrester)
"A computing architecture that coordinates large numbers of servers and storage to act as a single large computer." (Oracle, "Oracle Database Concepts")
"connecting different computer systems from various location, often via the cloud, to reach a common goal." (Analytics Insight)