(I hope!)

I recently installed a swag of programs to see how they handle the output from a friend's (one who is just starting out with a DSLR and a vintage one at that) Nikon D70.

At first I had ViewNX, from Nikon, as I understand.
Now I have installed RawTherapee and the latest, FastStone Image Viewer.

They all open up the output from the D70 that are listed as *.NEF files.

The Q is: what are these programs actually looking at?

And further, Is it the NEF (raw) file itself, or is it something called the embedded jpeg?

Note that the settings on the camera are to output raw only.

My suspicions are that the ViewNX program actually opens the full raw file, but I am not confident as to anything else, especially when the word "view" is attached.

Any insights would be appreciated.

Am.