A bicycle is a human-powered vehicle consisting of two wheels attached to a frame, propelled by pedaling action. Its operation involves converting mechanical energy, derived from the cyclical movement of the pedals, into rotational motion that drives the rear wheel. Modern designs incorporate complex mechanical systems, including gearing and braking mechanisms, which allow for efficient travel across varied terrain and speeds. As a technological artifact, it represents a relatively simple yet highly efficient mode of transport that continues to be studied for its applications in sustainable travel and physical fitness.