A self-propelled lawn mower is a type of lawn mower that has a drive system to propel it forward, allowing the operator to steer and guide it along the lawn. The drive system can be powered by gas or battery, and it works by engaging a speed control lever that causes the mower to move forward. Self-propelled mowers can be front-, rear-, or all-wheel drive, and they can have single or variable speed models. They are ideal for mowing large lawns or hilly terrain, as they can climb hills with very little effort on the operators part. Self-propelled mowers can save time and energy, as they mechanically move forward through challenging areas in the yard, such as thick grass. However, they require regular maintenance to ensure optimal performance, and gas-powered mowers require ongoing maintenance to ensure a long life. Push mowers, on the other hand, rely on manual effort to move and are more affordable than self-propelled mowers.