Closely related to blaster rifles, blaster pistols are smaller, less accurate, and less powerful. They are also much more concealable, and much cheaper, while still packing more than enough punch to kill a human.

In a galaxy consumed by conflict, weapons are a dangerous but necessary fact of life. The most common sidearm is the high-energy laser/particle beam weapon known as a blaster.

Blasters come in many different shapes, styles, and varieties, ranging from tiny "hold-out blasters" to incredibly powerful E-Web heavy repeating blasters. Vehicles and starships almost always weild incredibly powerful laser cannon blasters. Blasters offer many advantages, including reliability, portability, ease of maintainance and repair, and the ability to deliver a great deal of damage.

How it works:
When a blaster is fired, a small amount of high-energy blaster gas moves from the gas chamber to the gas conversion enabler (usually referred to as an XCiter). There the gas is excited by the weapon's power pack. The size of the power pack is proportional to the size and/or power output of the blaster: bigger blaster = more power. The laser cannons on starships like the Death Star and Star Destroyers each require their own reactor or power generator, delivering enough power to supply most small cities.

The excited gas passes into the actuating blaster module, which processes the gas into a beam comprised of intense energy particles coupled with light. The prismatic crystal housing focuses the beam, which is further focused, or "galvanized", as it passes through the blaster's barrel. The final particle beam, or "bolt", contains high-energy particles that cause damage to anything they hit; the bolt's visible light is a harmless by-product of this reaction.

Most blasters have an optimum range of 30 meters and a maximum range of 120 meters. The bolt will pierce stormtrooper armor or the force field and skin of a light spacecraft, but will not puncture the force field of a larger starship.

The blaster gas chamber on a standard BlasTech DH-17 Blaster Pistol holds enough gas for 500 shots, while the power pack will be drained in 100 shots. The pistol is normally semiautomatic (fires one shot every time the trigger is pulled), but fully automatic fire is available, albeit not reccomended, as the power pack will be drained in 20 seconds, and explosive overloads can occasionaly occur.

Thanks to Star Wars: The Essential Guide to Weapons and Technologyby Bill Smith, from which I gleaned this information.