What is the action of a firearm made up of parts?

The action of a firearm is the mechanism that loads, fires, and ejects cartridges. It consists of several key components, including the bolt or breech, firing pin, extractor, and ejector. Together, these parts work to chamber a round, ignite the primer when the trigger is pulled, and expel the spent casing after firing. The design of the action can vary significantly between different types of firearms, such as bolt-action, semi-automatic, or pump-action.