A gear is a critical mechanical component used to transmit power and motion between machine parts through the engagement of its teeth with another gear or component. Gears are commonly made from steel, cast iron, or other durable materials, designed to endure high loads and torque. They come in various types, including spur gears, helical gears, bevel gears, and worm gears, each serving specific purposes in applications like automotive, industrial machinery, and heavy equipment. Gears play a key role in improving efficiency, controlling speed, and optimizing force transmission in mechanical systems. Proper lubrication and maintenance are essential to extend their lifespan and ensure smooth operation.