"Electronic Sports, abbreviated
e-sports or
eSports, is used as a general term to describe the play of
video games competitively. Other terms include
competitive gaming,
cybersports and
V-Sports (used by the GGL).
These games which are considered electronic sports normally belong to the real-time strategy, first-person shooter, or sports game genres. They are played competitively at both amateur and professional levels. Professional levels are played competitively at the professional league and tournament." - Wikipedia
With leagues such as the World Cyber Games (WCG), Major League Gaming (MLG), Cyberathlete Professional League (CPL), Electronic Sports World Cup (ESWC) and many more around the world, they attract high number of spectators and participants on a global scale, making it the world's fastest growing competitive medium.
The eSports industry is unlike any other. With it's steady growth rate year by year, it only continues to expand and attract more and more people.
World Cyber Games 2008 Statistics

LAN, short for Local Area Network, is what gamers refer to competitions held at a dedicated venue where all competitors are required to attend physically. LAN's are held every week across Australia for games such as the Counter-Strike series and Warcraft 3: DotA. Winners are usually rewarded with either cash or product prizes either privately provided or sponsored.