RAW is unprocessed data that the camera captures.
Cannon and Nikon has their own versions of RAW Nikon is NEF and Cannon is CRW.
JPEG processed and compressed.
Adobe RGB has a larger array of colours compared to SRGB which is what most digital cameras use along with other computer programmes such as Apple Aperture.
Prophoto has a large amount of colour.
Save for the web
File -> save for the web.
can set file type and quality.