Crikey - without sounding big headed there is a bit of miss information here.
A RAW file does not contain extra information. It is simply the image straight from the camera's sensor with no in camera processing at all.
Each pixel of your sensor is only sensitive to one colour. This may be measured and recorded using 8,10,12 or even 14 bits per pixel. So you have an image that is composed of red, green or blue pixels. When you use jpegs your camera performs some calculations that basically averages out the colours by looking at the pixels around them. This is called interpolation or demosaicing. You end up with each pixel in full colour.
When your camera "fixes" its image including saturation, sharpness and the interpolated image it is essentially set. ANy changes you make on a computer change modify that image and you have less control over this.
With RAW this means is you can apply the changes later, on a computer. This gives you more control over the image, less loss of information and you can undo changes that don't work later.
The comment about 8bits per colour for jpeg is a mute point for most people as computer screens can not display more than 24bit and that is 8bits for red 8 bits for green and 8 bits for blue which totals at more than 16 million combinations of colour which for most people is just fine.
It is worth bearing in mind that for most people the extra fuss for RAW is too much but if you want control over your final image without loosing any detail or performing irreversible changes RAW is a good bet.
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