>What are the benefits of using this?
RAW is a totally uncompresed format where every individual pixel in the picture is saved.
It is mainly used by profesionals and graphic artists for pictures in magazines etc. On my camera they are about 14Mb in size I think.
Jpeg, the normal format, is actually a compressed format where the camera takes the orignal picture and puts if through some algorithms to reduce the picture size.
So for example if your picture has lots of blue sky all the same colour then the camera works out that rather than saving every individual pixel (as raw does), it saves one pixel and says the next 200 are all the same.
So a jpeg is not actually a true picture of what you took but a compressed format (rather like mp3 is a compressed audio format).
But it is good enough for the human eye.
But for real top quality then people use RAW.