Cloud storage
Also known as: the cloud, online storage, cloud backup, what is cloud storage
Cloud storage keeps your files on a provider’s servers and syncs them to your devices over the internet — iCloud, Google Drive, OneDrive, and Dropbox are the common services. It is separate from a device’s built-in storage, so moving files to the cloud can free local space, but only if local copies are removed.
- Files on a provider’s servers, synced over the internet
- Separate from a device’s built-in storage
- Frees local space only when local copies are removed
How cloud storage works
A cloud service stores your photos and files on remote servers and keeps them in sync, so the same library appears on your phone, tablet, and computer. Every account includes a free allowance — iCloud and OneDrive start at small free tiers, Google Drive more — with paid plans like iCloud+, Google One, and Dropbox adding capacity.
Cloud storage is online space, not space on your device. A phone can be full while the cloud has room, or the reverse. Buying more cloud storage does not enlarge the phone itself — it only gives the synced files somewhere to live.
When the cloud frees local space
Syncing alone does not reclaim space, because most services keep a full copy on the device by default. Space is freed only when the local copy is removed: features like Optimize iPhone Storage (iCloud Photos) or online-only files (OneDrive, Dropbox) keep a small placeholder on the device and the full file in the cloud.
Treat sync and backup as different jobs. A synced folder mirrors changes both ways, so deleting a file on one device deletes it everywhere — which is why a separate, independent backup still matters for anything irreplaceable.