differences between disk clone and disk image in Macrium Reflect

I am reading the Macrium Reflect doc:

A Disk Image stores the information required to completely restore disks (or their individual partitions) exactly as they were when the image was taken.

Cloning with Macrium Reflect creates an exact copy of partitions to a different drive. For example, Upgrading to a larger hard drive or moving from a large magnetic hard disk to a smaller and faster SSD. When you Clone a hard drive, you can boot from the target disk on the same system after cloning.

Are they saying the Disk Image is not bootable? If that is the case, how I can restore my new disk to working condition (needs to be booted from it) with the image created yesterday if my old C drive is damaged? I am using Windows 7.

Quite simply disk clone is disk to disk. Disk image is imaging the disk to a file, so that you can restore it later.

You pop in a recovery disk (which you can make from Macrium Reflect), point it at the target disk and restore.

Disk to disk cloning is handy for switching hardware. Depending on which version of macrium you have, imaging would let you do incremental/differential backups (which are faster and save space) and restore to different points of time without imaging the whole disk.

The disk image format Macrium uses is proprietary and not directly bootable, and that's pretty standard in the industry.

A Macrium "disk image" is a file, with a special format that only Macrium's software understands. As they say, it contains all the information necessary to re-create the disk and/or partitions that it is an image of. You need to run the Macrium software to do that, sometimes from a bootable CD/DVD if necessary. A disk "clone" is a byte-for-byte copy of whatever is on the cloned disk, with perhaps some limited adjustments to the partitioning scheme. As such, it should be possible to just replace the cloned disk with the clone and have it behave exactly the same.

In your case, you would need to boot into a different operating system partition that has Macrium Reflect installed, or use a Macrium rescue CD/DVD (or bootable usb device if they can do that these days) to restore your damaged C drive using the image file that Reflect made earlier.