# Cold Data **Domain:** Storage Architecture / Data Lifecycle **Doc Type:** Technical Concept Node **Maturity:** Established **Related:** [[Cerabyte]], [[Project Silica]], [[Physical Permanence Gradient]] --- ## Definition **Cold data** is data accessed infrequently enough that storage systems can trade immediate latency for lower cost, energy use, or higher durability. “Active cold” architectures shorten retrieval time while retaining deep-archive economics. ## Continuity relevance Longitudinal neural records may be cold most of the time yet require periodic large-scale retrieval for migration, validation, reconstruction, or model training. Access time, media longevity, and reader availability must be planned together.