Two or more eras is a term used to describe a period of time that is divided into two or more distinct parts. An EON is the longest division of geological time and is typically divided into smaller units such as eras, periods, and epochs. An AEON is a very long period of time, often used to refer to an indefinite and very long period of time. In this context, the terms EON and AEON can be used interchangeably to refer to two or more eras.