I'm glad you asked don't feel layman as you'll never learn much if you don't ask. RAW is a setting on mid to high range cameras were the sensor captures all the data it sees and records it on your memory card uncompressed.Most shoot .jpeg which the camera has processed and compressed for you.But a lot of information gets lost compared to editing it your self(you must have software that will work with Raw). You have the ability to really tweak your image before you compress and save in what ever compressed format you want eg. bitmap, jpeg, tiff. These all have different compression ratios. Also your original RAW image can not be altered so it's like keeping a negative in film photography. I hope that explains it. Others may want to add or correct me if I'm wrong. This is the way I understand RAW:shrug: