is not a nerd
A geek is obsessive over anything
and everything: television shows (including Star Wars, Harry Potter and Doctor Who) it can be from comics, the internet and often consoles, pc games or related topics.
The geek will know everything about the given subject
this will have few problems socially.
However, in brief, a nerd applies
to somebody who is a computer genius or enjoys maths,science
or ICT to a large