breaking it down:
nerd - Someone with a vast understanding of a subject, accompanied by an emotional disconnect from the topic. A nerd can strip and rebuild a computer without breaking a sweat or looking up a jumper setting, but wouldn't think to check out what's running on the box.
geek - Someone with a strong understanding of a subject and a passionate curiousity of all the factors involved. A geek can address the mechanical needs of a computer while also getting the spyware removed and replacing certain programs with their less-invasive counterparts.
dork - Someone with all the passion and interest in the world for a given subject, but with no practical nor intelectual deconstruction of the topic. A dork can have the most tweaked-out gaming system on the block, but neither know nor care to know how to open the tower and install more memory.
geek - Someone with a strong understanding of a subject and a passionate curiousity of all the factors involved. A geek can address the mechanical needs of a computer while also getting the spyware removed and replacing certain programs with their less-invasive counterparts.
dork - Someone with all the passion and interest in the world for a given subject, but with no practical nor intelectual deconstruction of the topic. A dork can have the most tweaked-out gaming system on the block, but neither know nor care to know how to open the tower and install more memory.