Definition - What does Celsius Scale mean?
Celsius Scale is a temperature scale which is used to determine the temperature difference between any two reference temperatures, i.e., freezing and boiling points. The scale is commonly defined by the two fixed points – the temperature at which water boils is 100 degrees and the temperature at which water freezes to form ice is zero degrees. The freezing and boiling point of the water is kept apart exactly by 100 degrees; hence, the degree on the scale is 1/100th of interval between the boiling and freezing points.
Petropedia explains Celsius Scale
The Celsius Scale was named after Swedish astronomer Andres Celsius who developed this temperature scale and various other temperature scales. The Celsius scale has replaced Fahrenheit for most of the applications in most countries. The Celsius scale was introduced in late 1960's and 1970's as a part of a move to regularize a standard metric measurement for temperature.
At present, the Fahrenheit Scale is used in the United States, Palau, Cayman Islands, Belize and Bahamas. United States' meteorologists use the Fahrenheit Scale for reporting and weather forecasting, whereas the other branches of science use the Celsius scale.