What is a century?

A century is a period of 100 years. A decade is 10 years.

* Historical periods are often defined as a century. However, because there was no 0th century, the century number is always 1 higher than the first two digits of the year number (e.g. 1950 is in the 20th century) except for years ending in 00, which are in the preceding century (1900 is in the 19th century with 1801-1899).