Pinions are gear wheels with a small number of teeth that mesh with a larger gear called a "cog".

It is a type of gear used in various mechanical systems to transfer motion or power from one component to another.

Pinions, like other gears, can be made from a variety of materials, such as steel, brass and plastic, depending on the requirements of the application.
Pinion is the element that is smaller than the other gears that make up the gear system.
Pinion is the gear in the gear system that transfers the first movement from the engine to the main gear, and since its diameter is smaller than the main gear, it rotates faster and provides torque to the gear system.
Pinions are gear types that are subject to more wear and damage because they rotate faster than the main gear.