dSLR cameras (and many compact digital cameras now on the market) allow you to choose either RAW or JPG format when capturing images. Jpg image files are 8 bit. As such they have 256 levels of brightness per rgb channel. Camera raw files on the other hand are 12 bit and have 4096 levels of brightness per channel.
The bonuses to shooting raw files are:
- exposure insurance - you can correct a file that is over or underexposed without loosing image quality
- perfect white balance - you can get perfect one-click white balance if you shoot raw files, that means perfect color in your photos, whether it's skin tone or landscapes.
- best quality - jpg is a lossy compression format, camera raw files do not loose any quality
- speed - it's much faster to edit a raw file than a jpg and with a jpg you have a lot more corrections to do
- non-destructive - you can't break a camera raw file. You can do a million corrections and do things different ways and you will always have all the data and quality of your original raw file.