What is Cloud Storage and How does It Work for Everyday Users?

Your phone photos back up on their own and a document you start on a laptop opens on your tablet. Cloud storage makes both possible. This guide explains what happens behind that convenience, what it costs you and how to use it safely.

What is Cloud Storage?

Cloud storage is a service that saves your files on servers in a remote data center that a provider like Google, Apple, Microsoft or Amazon operates. You reach those files over the internet from any device where you sign in.

Cloud sounds abstract but it only means storage you reach over a network instead of storage inside your device. NIST defines cloud computing as on demand network access to a shared pool of computing resources. Cloud storage applies that model to your files.

Microsoft documentation lists several storage types, including object storage for text and binary data, file shares and block storage for virtual machine disks. Consumer services like Google Drive and OneDrive show you folders and files while the provider handles the storage layer underneath.

How does Cloud Storage Work?

Three things happen when you save a file to a cloud service.

1. Upload. Your device sends the file over the internet to the provider's servers. Azure Storage rejects HTTP requests when secure transfer is required according to Microsoft. New storage accounts have that setting on by default. See Microsoft secure transfer guidance.
2. Store. Your provider saves the file in a data center and copies it. Microsoft states that Azure Storage always stores multiple copies of your data. Its zone redundant option copies data across three or more availability zones and its geo redundant option adds a second region hundreds of miles away. See Azure Storage redundancy.
3. Sync. After you edit a file, the service sends the update to your other signed in devices. Google states that offline edits apply once you are back online. See Google Drive offline article.

Other providers publish their own storage settings. Check the documentation of the service you use.

What are the Benefits of Cloud Storage?

• You get access from any device. Sign in on a phone, tablet or laptop and open the same files.
• You get a copy outside your device. Losing or breaking a laptop does not delete files that already reached the cloud.
• Sharing is easy. Send a link or let several people edit one file.
• Your storage has room to grow. Add space when you need it instead of buying another drive.

Providers also sell colder storage tiers for files you rarely open. See cold storage vs archive tiers for how those tiers differ.

What are the Downsides of Cloud Storage?

• You need a connection. Uploads, downloads and sync need internet. In Google Drive you can mark Docs, Sheets and Slides as available offline and open them without a connection.
• You pay over time. Plans past the free limit are subscriptions. Years of payments can pass the price of a one time drive.
• You trust the provider. Your files sit on servers that another company operates. Provider security and policies matter.
• Sync spreads mistakes. Deleting a file on one device syncs to the others. Google deletes trashed Drive files forever after 30 days according to its Drive deletion article. Microsoft says personal OneDrive accounts restore deleted files for 30 days and work or school accounts for 93 days unless an administrator edits that setting. See OneDrive restore article.

Is Cloud Storage Safe?

Large providers publish strong protections. Microsoft states that Azure Storage encrypts all data at rest with 256-bit AES by default and you cannot disable it. See Azure Storage encryption.

Your account is the bigger risk. Weak or reused passwords give anyone a way to sign in as you. Google says 2-Step Verification adds an extra layer of protection in case your password is stolen. See Google 2-Step Verification article.

Enable two step verification on every cloud account and set a unique password for every account. Encrypt sensitive files on your own device before you upload them or store them offline instead.

Is Cloud Storage the Same as Backup?

No. Cloud storage syncs your files so every device shows the same version. Backups store separate copies so you can restore after a mistake. Compare the two in the table.

Files damaged by malware can sync to the cloud like any other edit. See how ransomware works for why a separate copy matters. Microsoft notes that Microsoft 365 subscribers can restore an entire OneDrive to any point in the last 30 days, which gives you a recovery option inside that service.