Image
An image is a “mirror” of your drive (partitions). This “copy” contains all information taken from the original. A special feature of an image is that the file format is specially compressed and takes up much less disk space than the original. The more often you create images of your drive, the less you need worry about data loss. Should data on the original drive be lost or damaged, you can restore your last image with all its data onto your computer. With just a few mouse clicks, you can recover the original status of your drive before the last imaging.
An image can be made up of multiple image files (*omg). For example if one disk is not sufficient to store the image and more are needed, e.g. CD/DVDs.
The term image is also used in a wide sense for file backups.
Difference File backup and Drive image
Files are backuped directly in the form of data. This type of image includes only file information, no drive information is imaged. The file format is OBK (*.obk).
A drive image stores all used or all sectors of a drive. This automatically also creates an image of the file system and all files and folders. The file format is OMG (*.omg).