The format has a TIFF-image structure. It is generated by Canon cameras. The CR2 photo is stored in an uncompressed form and allows you to edit such settings as white balance, exposure, and other settings for photos that were already taken. It is the successor format to CRW, which was used in previous generation Canon SLR cameras.
This format is used to store small personal icons. It is used in website development to create favicons that are displayed in the address bar of the web browser as well as in satellite TV for identifying broadcast channels. It is very similar in structure to a GIF format image.