Geek comes from the root Geck, which is still used in the Netherlands; Gek, which means "Crazy", was also used in dialects of certain areas of Germany, to express "Geek's hat" that some men used in carnivals. This term was also used in the 18th century, in the countries of Austria and Hungary for those people who were fans of the circus, and already in the 19th century it was to refer to circus phenomena or strangers to the normal.
This is an Anglo-Saxon expression that varies its meaning in Latin America depending on the country and its culture. Today in the twentieth century we could say that a geek is a person who spends most of his time to be "sociable" with his computer; although these are not great experts in informatics or computing; and they are isolated from "normal" American society.
The degrees of "Geekism" range from fans of science fiction, lovers of video games, programmers and worshipers of comics.
Many times the term geek tends to be confused with the term nerd, so you have to pay some attention since they are completely different; Nerds don't have the same social status, and they are more obsessed with science or technology.
Geek became popular in the troops of the American armies for the acronym in English of “General Electrical Engineering Knowledge”. The term GEEK also denoted intelligent people, no matter what area they specialized in.