Difference Between Backup & Disk Image

Making copies of your data and moving those copies to long-term storage is called "backup." There are several ways to do this, which ranges from backing up individual files and folders to making entire drive images.

Backup Basics

The term "backup" can refer to any method of data archiving, whether it's individual files to entire hard drive volumes. A disk image is a type of backup.

Disk Image Basics

A disk image is the entire contents of a particular storage device that is in or attached to your computer. Therefore, a disk image can require a substantially larger amount of space than backing up some files and folders.

Backup Software

Windows XP, Vista Home Basic, and Vista Home Premium have backup software that can archive files and folders. The more expensive versions of Vista and all versions of Windows 7 have built-in software that includes drive image creation.

Drive Image Management

Since a drive image can be extremely large, you usually need to put it on a separate local storage device. Individual files and folders, meanwhile, can be small enough to archive through an Internet-based service such as Mozy or IDrive.

Incremental Backups

Modern disk image managers allow you to make "incremental" image backups, which update parts of the image rather than having to create a whole new one. This method gives you similar functionality to backing up individual files and folders.

References

• Microsoft.com: guide to data backup
• Apple.com: Time Machine backup
• Mozy.com: MozyHome FAQ