Springers are usually cheap (under £10, or about $25) pistols which are charged every shot by hand, by pulling the slide back. This compresses a spring and a catch holds the spring in place. On the forward movement of the slide, a bb is picked up from the magazine and chambered. When the trigger of the gun is pulled, the catch is released and the spring pushes a piston into a small air chamber. The air is compressed and pushed through a valve onto the bb, which is propelled forward. Occasionally, rifles and submachineguns are made into springers. These behave in exactly the same way except that a cocking lever is pulled back instead of a slide.
Springers are also used as sniper rifles which feature a realistic bolt - twisted and then pulled back - as well as shotguns. Shotguns can cost as much as £150 and sniper rifles can cost up to £300 new. A fully modified rifle with a real-steel military or professional scope can cost up to £1500-2000.