Persistent storage refers to any storage medium where data remains available even after a system restarts, shuts down, or crashes. Unlike RAM, which is volatile, persistent storage retains information across sessions using disks, SSDs, object storage, or distributed file systems. Applications rely on persistent storage to keep critical data such as user accounts, logs, configurations, and transactions safe over time.
Why it matters
Persistent storage is essential for application durability, disaster recovery, and long-term data retention. Without it, systems would be unable to store meaningful state or maintain consistency after failures. Understanding persistent storage helps developers choose the right technology for databases, backups, and cloud deployments.
Examples
Storing data in a relational database, writing logs to disk, or saving files in S3-compatible object storage. Lessons on What Is Storage? explain fundamental concepts.