Confidence votes 33. First of all you are probably a 'rent asking this and not every word in the dictionary a teen has a slang word for, so remember that and don't critcize them just because they are WAY cooler than the kids next door!
When Raw Disk Image type is not mentioned explicitly in this guide, we are referring to the Backup Disk Image. Another file format supported is ISO image. ISO images are used to store a copy of CD/DVD/Blue-ray disc in a file and stand apart from actual disk images.
The first CD-ROM disc introduced to the public had a storage capacity of 553 MB. Today, a standard CD-ROM disc can store up to 700 MB of data, or 80 minutes worth of audio. Non-standard CD-ROM discs also exist which can store up to 900 MB of data, or 99 minutes of audio.