Cloud storage keeps data on remote servers you access over the internet. The files are not on your laptop. They are in a data center, replicated across multiple drives and sometimes multiple regions. Dropbox, Google Drive, and OneDrive made it mainstream for consumers. AWS S3, Azure Blob Storage, and Google Cloud Storage run the enterprise side. You pay for capacity and access, not for hardware.

The model has real advantages. No capital expense for drives and servers. No capacity planning. No hardware refresh cycles. Scale up or down as needed. The trade-offs are equally real. You need internet access. You trust the provider with your data. Costs can spiral if you are not careful about egress fees and storage tiers. Security is shared: the provider secures the infrastructure, you secure the configuration. Misconfigured buckets have exposed millions of records. The provider did its job. The customer left the door open. Cloud storage is not inherently more or less secure than on-premises. It shifts the responsibility and changes the failure modes.

Cloud storage tiers

• Hot — frequent access, higher cost
• Cool — infrequent access, lower storage cost, retrieval fees
• Archive — rare access, cheapest storage, slow retrieval
• Deep archive — long-term retention, hours to restore

Cloud storage is someone else's computer. That is the point and the risk.