The three temperature scales are:
1) Kelvin (K) - Temperatures are defined relative to 0 Kelvin, which is also known as absolute 0. This theoretical temperature represents the point where thermal energy is so low, that molecules cease to move.
2) Centigrade or Celsius (C) - This scale is based on the physical properties of water. Zero C represents water's freezing point, while 100 degrees C is the boiling point of water.
3) Fahrenheit (F) - A scale based on the physical properties of brine. This scale was largely phased out in favor of the Celsius scale, and is used in less than a dozen countries.