The work formalizes a proposed framework in which the vacuum is treated as an informational substrate with finite conduction speed, from which mass, inertia, time dilation, and gravitational response arise. Mass is reinterpreted as localization (via inverse participation ratio), inertia as reconfiguration cost, and gravitation as a refractive response to gradients in informational load. Unlike conventional geometric approaches, the Informational Load Framework (ILF) does not assume spacetime curvature as fundamental, but instead treats relativistic phenomena as consequences of finite processing throughput. The framework reproduces familiar relativistic signatures (Lorentz factor, gravitational redshift, equivalence of inertial and gravitational mass) at the level of mechanism rather than postulate. It also removes singularities by saturating load rather than diverging geometry. Current version refactors the presentation for clarity, emphasizes ontology over phenomenology, and omits gravitational-wave derivations, which are relegated to future work. This release focuses on establishing core mechanism, definitions, and mathematical structure for ILF.