A century is a period of 100 years. Although a century can mean any arbitrary period of 100 years, there are two viewpoints on the nature of standard centuries. One is based on strict construction, while the other is based on popular perspective. While the century has been commonly used in the West, other cultures and calendars have utilized differently sized groups of years in a similar manner.
A year is the orbital period of a planetary body, for example, the Earth, moving in its orbit around the Sun. Year is a cycle in the Gregorian calendar of 365 or 366 days divided into 12 months beginning with January and ending with December