What & Why do need Backup—

What is Backup?

A backup is a copy of your data saved on another server, hard drive, or cloud. It helps restore your data if it’s lost, damaged, or deleted.

Why Do We Need Backup?

To protect our sensitive data against hardware failure, human error, cyberattacks, natural disasters, and software corruption.

Backup - Hardware Failure Example

My laptop's hard drive crashes, and I lose access to my photos and work files. Luckily, I had backed up everything on a USB drive last week. I buy a new laptop, connect the USB, and restore all my files in hours, keeping all my data safe.

Backup - Human Error Example

I accidentally delete my important work files and empty the recycle bin. Luckily, I had backed up everything to a cloud service last night. I log into the cloud, restore the deleted files in minutes, and keep all my data safe.

Backup - Cyberattack Example

In case of cyberattacks like ransomware. Suppose on 20th of July hackers lock or encrypt your files. If you have recent backups from 18th or 19th of July, you can restore your systems back to a point before the attack happened without paying ransom.

Backup - Natural Disaster Example

Fire or floods can destroy devices; backups stored off-site OR in Cloud can ensure data survival.

Backup - Software Corruption Example

Real-World Example: Imagine you update your company's web server on Monday, but the update crashes the website. Luckily you took a backup from Sunday, through which you can restore it and get the website running again quickly, saving time and preventing data loss.

What is Fault Tolerance?

Fault tolerance prevents data loss before failure by using hardware/software redundancy like RAID or load balancers.

Example of Fault Tolerance

Like a car with two engines — if one fails, the other keeps the car moving.

What is Disaster Recovery?

Disaster recovery restores data after a disaster using backups stored in safe locations.

Example of Disaster Recovery

Like a spare house key kept outside — used only after losing the original.