They're obsessed with something. It might be computers or computer games, comic books, anime, "Star Wars" or superheroes. It may even be a school subject or activity -- there are math geeks, band geeks and drama geeks.
Sometimes geeks' superior knowledge or devotion to something can create a wall separating them from outsiders. They may not always welcome your attempts to understand or get involved in their world.
Geeks usually aren't fashion-conscious and may be introverted. They often do well in school, especially in subjects that grab them, such as science, art or writing. The flip side to watch for is neglect of those subjects that don't turn them on. Same with socializing -- they may limit their friends to only those with similar interests.
