This chapter presents the core architectural framework of the Data Grid. Drawing on principles from electrical systems, communication layering, and system-of-systems engineering, it formalizes four methodological dimensions: lifecycle segmentation, semantic elevation, declarative system representation, and bounded AI integration. Together, these dimensions define structural boundaries that isolate volatility, preserve transparency, and ensure deterministic execution. The chapter reinterprets layered architectures as infrastructure doctrine rather than implementation convention and introduces the concept of a Deterministic Structural Core. By transferring mature engineering principles into distributed software-defined environments, the chapter provides a governing blueprint for stable and scalable data infrastructure construction.