What Is Cloud Storage and Do You Need It?

If you have ever opened a photo on your phone that you took on a tablet, or edited a document on a laptop and found the changes waiting on your work computer, you have already used cloud storage. The term sounds abstract, but the idea is plain: your files are kept on computers owned by a service provider, and you reach them over the internet instead of from a single drive in front of you.

How cloud storage works

When you save a file to a cloud service, an app on your device uploads a copy to the provider's data centres. Those are large buildings full of servers, usually spread across several locations so that a fault in one place does not wipe out your data. When you open the file on another device, the app downloads it or streams it to you. Most services also keep a local copy of files you use often so you can work offline and sync the changes later.

The main types you will come across

Many big providers combine several of these in one account, which is why the boundaries can feel blurry.

Sync is not the same as backup

This is the point that catches people out. A sync service mirrors your folders. If you delete a file on your laptop, it disappears on your phone too. If a file becomes corrupted, the corrupted version spreads. Most sync services keep a recycle bin and some version history for a limited period, which can save you, but they are not designed as a long-term archive.

A backup, by contrast, keeps independent copies and older versions so you can go back in time. For a full routine that combines both, see our guide on how to back up a computer.

Benefits

• Access from anywhere. Your files follow you between phone, tablet and computer.
• Protection from local disasters. A lost laptop or a failed drive no longer means lost work.
• Easy sharing. Send a link instead of an attachment, and control who can view or edit.
• Collaboration. Office tools that live in the cloud let several people edit one document at once. If your team works with desktop software, our tips for Office 2021 Professional Plus cover how local and online files can work side by side.
• Space on small devices. Phones can keep older photos online and download them only when needed.

Downsides and questions to ask

You depend on a connection

Without internet access, you can only open what has already been synced to your device. Large uploads can also be slow on a weak connection.

Costs can creep

Free allowances are often modest. Once you outgrow them, you move to a paid plan, and subscriptions across several services add up. Check what you actually use before paying for more than one.

Privacy and control

Your files sit on someone else's computers, so it is worth reading how a provider handles them. Useful questions:

• Is data encrypted in transit and at rest, and who holds the keys?
• Does the service offer end-to-end encryption for sensitive folders?
• In which regions is data stored, and does that matter for your work?
• Can you export everything easily if you decide to leave?

Account security matters more

If someone gets into your cloud account, they get into all of it. A unique, strong password and two-step sign-in are essential, not optional.

So, do you need it?

Most people benefit from at least some cloud storage, because most people own more than one device and would be upset to lose their photos. It makes particular sense if you:

1. switch between a phone, a laptop and perhaps a work computer;
2. share files with family, clients or colleagues;
3. have no off-site copy of irreplaceable pictures or documents.

It is less essential if you work on one machine, keep a disciplined local backup and rarely share files. Even then, a small cloud copy of your most important folders is a cheap insurance policy against fire or theft.

Getting started sensibly

Begin with the service already built into your phone or computer, since it will be the most seamless. Decide which folders actually need to sync, switch on two-step sign-in, and look at your storage use after a month. That tells you far more about whether you need to pay for extra space than any sales page will.