Science fiction conventions are gatherings of fans (called fandom) of various science fiction media, though the focus is on science fiction literature. The first science fiction convention was held in New York City, NY in 1939. It was organized by local science fiction clubs. Subsequent conventions were held in 1940 and 1941, then WW II postoned them until 1946 and they have been held yearly ever since. These main yearly conventions are called the World Science Fiction Covention or Worldcons and rotate among different large metropolitan cities in North America and, occasionally, around the world. When a convention is held out of North America, a mirror convention is held within North America that same year, though it isn't called a Worldcon. Also, since the founding of the first world convention, several smaller local or regional science fiction conventions have sprung up over the years and are held around the U.S. at various places and various times during the year.
At these conventions, fans of science fiction come together with professional creators of science fiction (writers, artists, filmmakers, etc.) to discuss its many aspects, debate the merits of past or recent works, as well as market new or future works of science fiction. Exclusively at the Worldcon, a vote is taken in several categories (short story, short novel, novel, etc.) on the best science fiction literature of the previous year(called the Hugo awards).
Fantasy media has in the past been included as part of the agenda at these conventions but as fantasy literature grew in popularity in the 1970's, a separate World Fantasy Convention was begun in 1975, held yearly thereafter. As such, fantasy is little emphasized at today's conventions.
Also, several works of science fiction (usually movies or television shows) have gained such a large fan base that they have conventions based solely on that work(Star Trek, Star Wars, etc).
