Celsius is the temperature scale most of the world uses in daily life: water freezes at 0° and boils at 100°. Weather, ovens, and school science in Taiwan all use it. In English you say twenty degrees Celsius, or 20°C. Older British English also said centigrade — same scale, older name. Scientists now prefer Celsius. It is named after Anders Celsius, a Swedish astronomer. Though actually, his first version was the other way round: 0 was boiling and 100 was freezing, and later people flipped it. We still write a capital C because it began as a person’s name.