What backing up means and why it matters

A backup is a copy of your files stored somewhere other than your main computer or phone. If your device fails, gets stolen, or you accidentally delete something, a backup lets you recover that work. Without one, a hard drive crash or a ransomware attack can mean permanent loss.

Backups work in three basic ways: copying files to an external drive you plug in, syncing files to cloud storage that updates automatically, or using backup software that handles both. Most people use a combination — a cloud service for daily work files and an external drive for everything else, checked once a month.

The method you choose depends on how much data you have, how often it changes, and whether you want the backup to happen without you thinking about it. A freelancer with constantly changing project files needs something different from someone who mostly stores photos and documents that don't change often.

Key Takeaways

  • External hard drives are the cheapest way to back up large amounts of data, but you have to plug them in and start the backup manually.
  • Cloud storage services like Google Drive, OneDrive, and iCloud back up automatically once you set them up, but they charge monthly for large amounts of data.
  • The safest approach combines both: cloud for files you use daily, and an external drive for everything else, checked monthly.
  • Backup software like Backblaze or Acronis automates the entire process and stores copies off-site, but costs money and takes time to set up.
  • Test your backup by actually restoring a file from it before you need it — many people discover their backup doesn't work only after a disaster.

Using an external hard drive

An external hard drive is a portable storage device you plug into your computer with a USB cable. They cost between $50 and $150 depending on size, hold terabytes of data, and require no monthly fees. The trade-off is that you have to remember to plug it in and start the backup yourself.

To set up a backup on Windows, plug in the external drive, open File Explorer, and copy your important folders (Documents, Pictures, Desktop) directly onto it. On a Mac, use Time Machine: plug in the drive, go to System Settings > General > Time Machine, click "Add Backup Disk", and select your external drive. Time Machine then backs up automatically every hour when the drive is plugged in.

External drives fail eventually — typically after three to five years of regular use. For that reason, do not rely on a single external drive as your only backup. Pair it with cloud storage, or keep two external drives and rotate them monthly so one is always stored away from your computer.

Cloud storage services

Cloud storage means your files live on a company's servers and sync to your devices automatically. Google Drive, Microsoft OneDrive, and Apple iCloud are the most common. They all work the same way: you install the app, choose which folders to sync, and files update across all your devices whenever you change them.

Google Drive gives you 15 GB free and costs $2 per month for 100 GB. OneDrive offers 5 GB free and $2 per month for 100 GB. iCloud starts at 5 GB free and $1 per month for 50 GB. All three let you recover deleted files for 30 days after you delete them, which saves you from accidental loss.

The main limitation is that cloud storage syncs whatever you do — if you accidentally delete a file or a virus encrypts your files, the deletion or encryption spreads to the cloud within minutes. For that reason, cloud storage is best paired with a separate backup (like an external drive) that does not sync in real time.

If you use multiple devices, cloud storage is the easiest way to keep files consistent across them. A document you edit on your laptop appears on your phone and tablet within seconds.

Backup software that handles everything

Backup software like Backblaze, Acronis True Image, or Carbonite automates the entire process. You install the software, tell it what to back up, and it runs in the background, uploading copies to the company's servers. You never have to plug in a drive or remember to start a backup.

Backblaze costs $7 per month and backs up everything on your computer to their servers. Acronis True Image costs $50 to $100 per year and can back up to an external drive, a network location, or the cloud. Carbonite costs $6 per month for unlimited data. All three let you restore individual files or your entire computer if it fails.

The downside is cost and time. Backblaze's initial backup can take weeks if you have a lot of data, because it uploads over your internet connection. Acronis requires more technical knowledge to set up properly. For most people, these tools are overkill unless you run a business or have data you cannot afford to lose.

What to back up and how often

Back up anything you cannot easily recreate: documents, photos, videos, financial records, and work files. Do not bother backing up programs — you can reinstall them from the internet if you need to. Do not back up your operating system if you are using cloud storage or backup software, because they handle that automatically.

If you use cloud storage, your files back up continuously as you work. If you use an external drive, back it up at least monthly — set a calendar reminder on the first of each month to plug it in and let Time Machine (Mac) or File History (Windows) run for an hour. If you use backup software, set it and forget it — it runs automatically.

The more often your files change, the more often you should back up. A writer working on a manuscript every day should back up weekly. Someone who takes photos once a month can back up monthly.

Testing your backup so you know it works

A backup that you have never tested is not a backup — it is a hope. Before you need it, actually restore a file from your backup to make sure it works. Pick a document or photo you do not need, delete it from your computer, then recover it from your backup.

On a Mac with Time Machine, open Finder, navigate to the folder where the file was, click the Time Machine icon in the menu bar, and select an earlier time when the file existed. On Windows with File History, right-click the folder, select "Restore previous versions", and pick the version you want. With cloud storage, go to the web version of Google Drive or OneDrive, find the file, and click "Restore".

If you cannot restore the file, your backup is not working. This is the moment to fix it, not the moment after your hard drive crashes. Many people discover their backup failed only when they actually need it.

Backing up on phones and tablets

Phones and tablets back up differently than computers. On an iPhone or iPad, go to Settings > [Your Name] > iCloud > iCloud Backup and turn it on. Your device backs up automatically when plugged in and connected to Wi-Fi. On Android, go to Settings > Google Account > Manage Your Google Account > Backup and turn on "Backup by Google One".

These backups cover your photos, messages, app data, and settings — everything except apps themselves, which reinstall from the app store. If you lose your phone, you can restore to a new one by signing in with the same account.

For photos specifically, Google Photos and Apple Photos both back up your entire library to the cloud automatically. Both offer free storage with limits, then charge monthly for more. This is separate from your device backup and protects your photos even if you delete them from your phone.

Frequently Asked Questions

How much storage do I actually need?

Check how much space your files use right now: on Windows, right-click your user folder and select "Properties"; on Mac, select the folder and press Command-I. Most people use between 100 GB and 500 GB. Buy an external drive with at least twice that capacity so you have room for future files. For cloud storage, start with 100 GB and upgrade if you run out.

What if I have files on multiple computers?

Cloud storage is the easiest solution — install it on each computer and all files sync to the same folder. If you prefer external drives, back up each computer to its own external drive, or use backup software that can handle multiple machines. Do not back up one computer's drive to another computer's external drive, because if one computer fails, you lose both copies.

Can I back up to a network drive instead of an external drive?

Yes, if you have a network-attached storage device (NAS) or a shared folder on another computer. Time Machine on Mac and File History on Windows both support network locations. The advantage is you do not have to plug anything in. The disadvantage is that network backups are slower and require your network to be working.

What happens if the cloud storage company goes out of business?

You lose access to your files. For that reason, never rely on a single cloud service as your only backup. Always keep a separate copy on an external drive or with a different service. This is why the combination approach — cloud plus external drive — is safer than either one alone.

Do I need to encrypt my backup?

If your backup contains sensitive information like financial records or passwords, encryption protects it if the drive is stolen. Most external drives come with encryption software. Cloud services encrypt data in transit and at rest, but check their privacy policy to see if they can read your files. For maximum security, use backup software that encrypts before uploading.