A piston is a cylindrical component found in engines, pumps, and other machinery. It moves up and down within a cylinder, creating pressure that helps convert fuel into energy. In a car engine, for example, the pistons are crucial for the combustion process, where fuel ignites and pushes the pistons down, turning the crankshaft and ultimately powering the vehicle. Pistons are typically made of metal and are designed to withstand high temperatures and pressures. They are often connected to a connecting rod, which transfers the motion to the crankshaft. This simple yet effective mechanism is essential for the operation of many machines, including those in the automotive and industrial sectors.