I am sick of trying to find good alternatives, and I really really want to install photoshop (have sub through work) but I really really _really_ don't want to install creative cloud.
@mike Much bigger dynamic range, and more data to work with than a JPEG - so it's easier to brighten the dark areas or darken the bright areas of an image later, for instance. Basically, more info stored in the image than in a JPG or TIFF.
More complexly, it's the raw data from the sensor of the camera, before any processing or denoising etc is applied.
I don't often use them, but in this case I've got some sunset/snowy pictures I'd like to play with contrast and exposure on.