Nikola Tesla was an electrical pioneer who made significant contributions to the development of electricity and magnetism in the late 19th and early 20th centuries. He is best known for his work on alternating current (AC) electricity supply systems, which revolutionized the way electricity was used and distributed. He also developed the Tesla coil, a device that produces high-voltage, low-current electricity. Tesla's inventions and discoveries have had a lasting impact on modern technology, and he is widely regarded as one of the most influential scientists of all time.