Picture this: it is the night before your project is due, and your laptop will not switch on. Is your work gone forever? If you made a backup, you can relax. If not… Today you learn how to make sure that never happens to you.
In this post:
- Why we need secondary storage
- What a backup is and why we make one
- Choosing the right backup media, including the cloud
- How to restore your work
- Two activities and a quiz
Why secondary storage matters
The computer’s main memory (RAM) only holds data while the power is on. Secondary storage (hard disks, SSDs, flash drives, discs and the cloud) keeps your files when the power goes off, so you can open them again tomorrow, next term or next year.
What is a backup?
A backup is an extra copy of your files, kept somewhere other than the original, so you can get them back if something goes wrong. Getting the files back from the backup is called restoring.
Why back up? Because things go wrong:
- a hard drive or laptop breaks down;
- you delete or save over a file by mistake;
- a virus or other malware damages or locks your files;
- a phone or laptop is lost or stolen;
- a power surge, fire, flood or hurricane damages your equipment.
Backup media: which one?
| Media | Typical capacity | Good points | Not so good |
|---|---|---|---|
| CD | About 700 MB | Cheap; good for a few documents | Small; many new computers have no disc drive |
| DVD | About 4.7 GB (single layer) | Cheap; holds photos and short videos | Needs a disc drive; scratches easily |
| Blu-ray disc | 25 GB or 50 GB | Holds HD video and large projects | Needs a Blu-ray drive; discs cost more |
| External hard disk | 1 TB to several TB | Huge space for the price; good for backing up a whole computer | Can be damaged if dropped |
| USB flash drive | About 16 GB to 1 TB | Small, tough, easy to carry | Easy to lose; not ideal as your only backup |
| Flash memory card (SD, microSD) | About 16 GB to 1 TB | Tiny; used in phones, cameras and drones | Very easy to lose |
| Cloud storage | Free plans of about 5–15 GB; more if you pay | Safe from fire and theft at home; open your files on any device | Needs Internet; you must protect your password |
Capacity reminder: 1 GB (gigabyte) = about 1,000 MB (megabytes), and 1 TB (terabyte) = about 1,000 GB.
Image source: File:USB flash drive, 1TB.jpg (Wikimedia Commons)
Backing up to the cloud
Cloud storage keeps your files on a company’s computers (servers) on the Internet. Examples are Google Drive, Microsoft OneDrive and Apple iCloud. Your school account may already include one.
- Your work is safe even if your device is lost, stolen or damaged in a storm.
- You can open your files on a phone, a laptop or a school computer.
- Protect your account with a strong password and two-step verification.
- Careful: syncing is not always a backup. If a folder is synced and you delete a file on your laptop, it may be deleted from the cloud too. Keep an extra copy of really important work.
The 3-2-1 rule
A simple rule many IT professionals follow: keep 3 copies of important files, on 2 different kinds of storage, with 1 copy kept somewhere else (for example in the cloud or at a relative’s home).
How to restore your work
- From a USB drive or external hard disk: plug it in, open it in File Explorer, and copy the files back to your computer.
- From the cloud: sign in and download the file. If you deleted it, look in the Bin (Google Drive) or Recycle bin (OneDrive) and choose Restore. Deleted files usually stay there for about 30 days.
- An older version: Google Docs and many cloud services keep a version history, so you can go back to an earlier copy if you saved over something by mistake.
- Test it! Every so often, try opening a file from your backup. A backup you cannot restore is no use.
Watch: the 3-2-1 backup rule
In this video, a computing teacher explains the 3-2-1 rule for backups. What three copies would you make of your project?
Video: Data Backup: The 3-2-1 Rule – ExplainingComputers – https://www.youtube.com/watch?v=rFO6NyLIP7M
Activity: choose the best backup media
Try it: which media fits best?
Choose the best storage media for each situation.
| You want to carry your project to school and back every day | |
| Your family wants to back up 600 GB of photos and videos from the home computer | |
| You want your homework safe even if a hurricane hits your home, and to open it on any device | |
| You want to give your grandmother 3 GB of photos on a disc for her DVD player | |
| Your school wants to keep 40 GB of HD sports-day video on a single disc | |
| Your drone needs a tiny removable card to store its videos |
Activity: restore a deleted file
Try it: put the steps in order
You deleted your English essay from Google Drive by mistake. Use ▲ and ▼ to put the steps for getting it back in the right order, then click “Check my order”.
▲ First step
- Sign in to Google Drive
- Open the Bin
- Find your essay in the list
- Right-click the essay and choose Restore
- Check that the essay is back in My Drive
▼ Last step
Group chart
In your group, make a chart of the storage media in this lesson. For each one, show its capacity, one good point, one bad point, and one situation where it is the best choice for a backup.
Self-check quiz
Click the best answer. You get feedback straight away; only your first click counts towards your score.
1. What is a backup?
2. What does restoring mean?
3. Which media holds the most data?
4. What is one advantage of cloud storage?
5. In the 3-2-1 rule, what does the “1” stand for?
6. Why is it a good idea to test your backup?
Related posts on islandclass.org
- Data and Software Maintenance – includes a section on backups
For later, in Forms 4–5 (CSEC IT): these go deeper and are for when you reach CSEC Information Technology.
- Cloud Storage vs Local Storage: Capacity, Cost, Access and Security
- Secondary Storage
- Local Storage and Cloud Storage
- Video: Cloud Storage
Next: Your First Word Document: Create, Edit, Save and Print
Syllabus link: Forms 1–3 ICT curriculum, Module 2, Objective 2.10 – select appropriate media to back up and restore data. (This objective is printed as 3.0 in the curriculum document.)
Attributions to media used in this post:
- USB flash drive, 1TB.jpg – EU+Mexico – CC0 (via Wikimedia Commons)
- Video: Data Backup: The 3-2-1 Rule – ExplainingComputers (YouTube)
Updates
2026/10/21
– Fixed the activity code so its buttons keep working.
© 2026 Vedesh Kungebeharry. All rights reserved.