Celsius

Like with most articles on the Internet if you really want to know about stuff you will eventually read it on the Wikipedia...so here it is for you: celsius on the wiki.

Celsius is a temperature scale where 0 °C indicates the melting point of ice and 100 °C indicates the steam point of water.

The temperature of "absolute zero" is at -273.15 °C which is a state where no energy remains in a substance. (This by the way is precisely 0 Kelvin)

The Celsius scale was developed by a Swedish scientist called Andreus Celsius.