Nerd -- 1. (n) a socially unaware or socially indifferent individual whose interests pertain to discovering in detail the quirks of a chosen subject matter, preferring to gain knowledge than to wear important clothes or impress others. Examples include Star Trek nerds, gamers, those who build their own computers, and people who write massive Azumanga Daioh essays about Sakaki-san for the fun of it when they really should be paying attention in English 111, planning on turning this in for an assignment whenever it fits the standards of an assignment.
2. (n) a more specific subsection of nerds (referred to by the same word) whose obsession with their topic is more mental and intellectual rather than about owning gear or engineering electronics. Examples include history nerds, those who pursue PhDs, and people who can psychoanalyze every single character in StarCraft but stink horribly at the game when they actually try to play it. Nerds are generally obsessed with words, history, or the story of an already created fictitious universe. See: Geek.
Geek -- (n) a socially unaware or indifferent individual whose interests pertain to discovering in detail the quirks of a chosen specific subject matter, but less in a mental way and more physically. Geeks prefer to play games than to dwell on every detail of the plot, and it is they who are better with computers and other electronic technology rather than history or writing. Examples include Best Buy's Geek Squad, gamers who hold LAN parties, and people who will bore you to tears trying to explain to you the difference between RAM and ROM. While the first definition of the word "nerd" can be applied to them in an overall sense, "geek" is more specific to their nature.
So is this consistent or different from your own view of nerds vs geeks?