system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is the difference between Celsius and centigrade?

It seems interchangeable, I'm just curious when to use each, and if there are specific rules about it.
gpt
The terms are interchangeable.  The term Celsius comes from scientist Anders Celsius, who studied and helped develop the temperature scale.  Centigrade come from the Latin term meaning *a hundred steps*.  The hundred steps are the hundred degrees it takes for water to go from freezing to boiling.

Basically, you can either use the term that is named after the creator, or use the term that describes the scale.