There are three basic parts of a handgun.
The barrel is the tube-shaped part of the handgun through which a bullet is fired. It is attached to the handgun’s frame and can vary in length. The longer the barrel, the more accurate the handgun in hitting a target.
The frame give the handgun its structure. All other parts are attached to or housed in the frame.
A handgun’s action loads, fires and ejects a cartridge.