There is no difference between centigrade and Celsius. They are two different names for the same temperature scale. The term “centigrade” was commonly used in the past to refer to the Celsius scale, but it has fallen out of use in recent years. The Celsius scale is named after the Swedish astronomer Anders Celsius, who first proposed it in 1742. It is a metric system temperature scale where 0 degrees Celsius represents the freezing point of water and 100 degrees Celsius represents the boiling point of water at sea level.