What Is Airsoft
Airsoft is a game where people shoot each other with replicas of real guns using non-lethal 6mm plastic pellets known as BBs. Games played with these guns are called "skirmishes", and protective gear must be worn in order to avoid serious injury. It is recommended that you cover as much skin as possible to eliminate pain caused if it is directly struck by a BB.
There are three types of airsoft guns; Auto Electric Gun (AEG), Gas powered, and Spring powered.
AEG's are most popular, mostly with pro players. They are also most expensive, a decent on costing around $300. They are powered by battery, and must be charged before use. AEG's shoot both semi- and full-auto, and have RPM's (Rounds per Minute) similar to their real counterpart.
Gas powered guns are mid-priced. They rely on compressed air, such as CO2, to propel the BB. They are semi-auto, and can store the gas in the magazine or on the gun.
Spring powered guns are a very commonly gun bought by beginners. They are the cheapest, starting at $10, and is easily maintained. You don't have to worry about running out of battery or gas. However, you must cock the gun after each shot in order to shoot again. Among pros, spring powered guns are used by snipers. If you are a beginner, you should probably buy a spring powered gun.