In simplest terms, the boiling point of a liquid is the temperature at which it converts from liquid phase to gas phase. For example, at its boiling point, water (liquid) converts to water vapors (gas phase).
There are three different temperature scales that are widely used, including Celsius, Fahrenheit and Kelvin. These scales have been defined by keeping in mind the properties of water.
The boiling point of water in Celsius, Fahrenheit and Kelvin scales are 100 degree Celsius (or C), 212 degree Fahrenheit (or F) and 373 Kelvin (or K).
Given the temperature in one scale, we can easily convert it to other scales. For example, if the temperature in Celsius scale is given, it can be converted to Fahrenheit scale by using the relation:
F = 9/5 C + 32
where F and C are temperatures in Fahrenheit and Celsius scales.
Similarly, K = C + 273
where, K is the temperature in Kelvin scale.
Hope this helps.