Leonardo da Vinci's ornithopter was a winged machine designed to imitate a bird's flight.
Leonardo studied birds extensively and sketched several machines with flapping wings. His ornithopter concepts used human-powered mechanisms such as pedals, levers, and gears to move large wings. He believed careful observation of anatomy and airflow could help humans reproduce the principles of natural flight.
A human-powered flapping machine would require more energy than a person can normally provide, and Leonardo's designs were never proven to fly. Their importance lies in the systematic way he analyzed lift, balance, wing structure, and the movements of birds.
An ornithopter is not the same as a glider or helicopter. A glider relies on fixed wings and air currents, while a helicopter uses rotating blades. An ornithopter produces lift through flapping wings, whether powered by a person, an engine, or another mechanism.