According to Wikipedia, a Stun Gun is an electroshock weapon. It is an incapacitating weapon that momentarily disables a person with an electric shock.Stun Guns are hand held devices that do not necessarly resemble a gun at all. They generate a visible arc between two electrodes while making a somewhat menacing cracking noise.
The difference between a Tazer and a Stun Gun is that a Tazer actually resembles a handgun and fires (via a gas cartridge) a couple of small electrodes into the target's skin, while attached to the gun by a few feet of conductive wire. They also have the capabilitiy to be used as a StunGun that is called, “drive stun”, when it is pressed to someone while holding down the trigger.
Stun Guns are legal in most states, however, in a lot of states they are illegal or have restrictions. If you are considering owning a Stun Gun it would be wise to look up the laws in your state. I hope this post helps you.