In this chapter, we discussed the core OGSA platform components that are identified as suitable candidates for implementation with any OGSA-based infrastructure. These provide value-added functionalities and enhance the common utility of the grid. We are acknowledging that the OGSA WG may identify other functional services and components over a period of time, and may standardize upon them, define behaviors, service interfaces, and information schema. This will occur and enrich the OGSA architecture model. As we have seen earlier, use cases are core for this evolutionary architectural transformation activity.