Main function: A piston moves up and down inside an engine cylinder. It receives the force produced when fuel and air burn inside the engine and transfers that force through the connecting rod to the crankshaft.
This helps the engine produce power and move the vehicle.
2. Parts and their functions
Looking at the pistons in your picture, these are the important components:
Component Function
Piston crown (top) Receives combustion pressure and heat
Piston rings Seal combustion pressure and control engine oil
Ring grooves Hold the piston rings in position
Piston skirt Guides the piston inside the cylinder
Wrist pin hole Holds the pin connecting the piston to the connecting rod
Valve reliefs Provide clearance for the engine valves