The Grid concept is motivated by the need for flexible, secure, coordinated resource sharing among dynamic virtual organizations (VOs). Grid technologies address challenges such as authentication, authorization, resource access, and discovery in environments where resources are shared across institutions. The Grid architecture is designed to be extensible and open, with protocols, services, and APIs categorized by their roles in enabling resource sharing. Intergrid protocols are essential for interoperability between different Grid systems. Grid technologies complement other technologies like enterprise computing, peer-to-peer, and application/storage service providers, offering flexibility and control over resource sharing. Virtual organizations (VOs) vary widely in purpose, scope, and structure, but they all require flexible sharing relationships, fine-grained access control, and diverse usage modes. Current distributed computing technologies do not adequately address these needs. Grid technologies, developed over the past five years, provide solutions for secure resource sharing, including protocols for resource management, information query, and data management. Grid technologies are not competitive with existing distributed computing technologies but can enhance them by enabling resource sharing across institutional boundaries. The Grid architecture is structured into layers: Fabric, Connectivity, Resource, Collective, and Applications. The Fabric layer provides access to local resources, while the Connectivity layer handles communication and authentication. The Resource layer defines protocols for secure sharing of individual resources, and the Collective layer coordinates multiple resources. The Applications layer includes user applications that operate within VO environments. Grid technologies are essential for enabling dynamic, cross-organizational resource sharing and problem-solving in diverse environments. They provide a flexible framework for resource sharing, with protocols and APIs that support interoperability and standardization. The Grid architecture is designed to be extensible, allowing for the integration of new technologies and services. Intergrid protocols are crucial for ensuring that Grid systems can interoperate and share resources. The Grid concept is fundamental to modern computing, enabling collaboration in resource-rich environments and addressing the needs of diverse disciplines and activities.The Grid concept is motivated by the need for flexible, secure, coordinated resource sharing among dynamic virtual organizations (VOs). Grid technologies address challenges such as authentication, authorization, resource access, and discovery in environments where resources are shared across institutions. The Grid architecture is designed to be extensible and open, with protocols, services, and APIs categorized by their roles in enabling resource sharing. Intergrid protocols are essential for interoperability between different Grid systems. Grid technologies complement other technologies like enterprise computing, peer-to-peer, and application/storage service providers, offering flexibility and control over resource sharing. Virtual organizations (VOs) vary widely in purpose, scope, and structure, but they all require flexible sharing relationships, fine-grained access control, and diverse usage modes. Current distributed computing technologies do not adequately address these needs. Grid technologies, developed over the past five years, provide solutions for secure resource sharing, including protocols for resource management, information query, and data management. Grid technologies are not competitive with existing distributed computing technologies but can enhance them by enabling resource sharing across institutional boundaries. The Grid architecture is structured into layers: Fabric, Connectivity, Resource, Collective, and Applications. The Fabric layer provides access to local resources, while the Connectivity layer handles communication and authentication. The Resource layer defines protocols for secure sharing of individual resources, and the Collective layer coordinates multiple resources. The Applications layer includes user applications that operate within VO environments. Grid technologies are essential for enabling dynamic, cross-organizational resource sharing and problem-solving in diverse environments. They provide a flexible framework for resource sharing, with protocols and APIs that support interoperability and standardization. The Grid architecture is designed to be extensible, allowing for the integration of new technologies and services. Intergrid protocols are crucial for ensuring that Grid systems can interoperate and share resources. The Grid concept is fundamental to modern computing, enabling collaboration in resource-rich environments and addressing the needs of diverse disciplines and activities.