How long is a century?

A century is equal to 100 years. The word "century" comes from the Latin word "centuria," which is a unit composed of 100 parts. The word "century" includes the numeral prefix "cent" which indicates a value of 100.

For example, the word "centennial" is a celebration commemorating a 100-year anniversary. The prefix "cent" or "centi" can also mean one-hundredth, as in the word "centimeter," which is one-hundredth of a meter.

Similarly, a millennium is equal to 1000 years. The word "millenium" comes from the Latin word "mille," which means 1000, and can be used to express a vast number of something.