Driven gears are mechanical components that transmit motion and force between rotating shafts. They work by interlocking teeth, allowing one gear to turn another. This interaction is essential in various machines, from simple toys to complex automotive systems, where they help control speed and torque. In a gear system, the gear that receives power is called the driven gear, while the gear that provides the power is known as the drive gear. The size and number of teeth on each gear determine the mechanical advantage and speed ratio, making driven gears crucial for efficient operation in devices like bicycles and watches.