Georg Simon Ohm was a German physicist and mathematician who is best known for his work in electricity and magnetism. He formulated Ohm's Law, which states that the current through a conductor between two points is directly proportional to the voltage across the two points. Ohm's Law is one of the most fundamental laws of physics and is used in many areas of electrical engineering. Ohm also made important contributions to the understanding of electromagnetism and thermodynamics. He is considered one of the most influential scientists of the 19th century.