Answer
Electromagnetism, the answer to Ørsted's discovery, revolves around the profound connection between electricity and magnetism. This fundamental principle elucidates that an electric current can induce a magnetic field, and conversely, a changing magnetic field can generate an electric current. Ørsted's groundbreaking experiment showcased this phenomenon, paving the way for numerous technological marvels, including electric motors, generators, and transformers, which shape our modern world.