What Is Cloud Storage? A Plain-English Guide
What 'the cloud' really means, how services like Google Drive, iCloud, OneDrive and Dropbox work, and how to choose and use one safely.
"It's saved in the cloud" just means your files are stored on someone else's computers, in large, secure data centres run by companies like Google, Apple, Microsoft and Amazon, and you reach them over the internet. There's no actual cloud; it's a nickname for "servers somewhere else".
Why use cloud storage?
- Your files survive accidents. If your phone or laptop is lost or broken, your files are still safe.
- Access from anywhere. Start a document on your laptop and finish it on your phone.
- Easy sharing. Send a link instead of a huge email attachment.
- Automatic syncing. Change a file in one place and it updates everywhere.
The main services
| Service | Best if you use… | Notes |
|---|---|---|
| iCloud Drive | iPhone, iPad, Mac | Built in to Apple devices; also works on Windows |
| Google Drive | Android, Gmail, Chrome | Free storage shared with Gmail and Google Photos |
| OneDrive | Windows, Microsoft 365 | Built in to Windows; large storage included with Microsoft 365 |
| Dropbox | Mixed devices | Simple, works everywhere, popular for sharing |
All of them offer some free storage and paid plans for more. Prices change, so check each provider's website. Usually the best choice is simply the one that's built in to the devices you already own.
Sync is not the same as backup
This catches lots of people out. With syncing, if you delete a file on your laptop, it's deleted from the cloud and your other devices too. Most services keep deleted files in a bin for a limited time, so you can often get them back, but don't rely on sync as your only copy of anything precious. See the 3-2-1 rule in our backup guide.
Is the cloud safe?
The big providers protect their data centres far better than most of us could protect a computer at home. The weak point is usually your password. Keep your cloud account safe by:
- using a strong, unique password (here's how)
- turning on two-step verification
- checking who you've shared files with now and then, and removing old links
How businesses use the cloud
For businesses the cloud goes far beyond file storage. Platforms such as Amazon Web Services (AWS), Microsoft Azure and Google Cloud rent out computing power, databases and AI tools by the hour. That lets a small company run the same kind of systems as a large one without buying servers. If you're curious about a career in this area, entry-level certifications such as AWS Certified Cloud Practitioner are a popular starting point.