What processes occur in the engine during each of the four strokes? What are these bars called?

Piston strokes are named according to the processes occurring in them: intake, compression, stroke and exhaust. Inlet – the piston moves down, a vacuum is created in the cylinder, the valve opens and the combustible mixture enters the cylinder, the valve closes, the crankshaft makes half a turn. Compression – the crankshaft continues to turn, the piston moves up and compresses the combustible mixture, it ignites from a spark and burns quickly. Working stroke – the piston under pressure of gases goes down, transmitting a push to the connecting rod and the crankshaft with a flywheel when the valves are closed. At the end of the third stroke, another valve opens to release the combustion products to the atmosphere. Exhaust – the piston moves up, the combustion products exit through the valve, at the end of the stroke, the valve closes.