The term 'Important Historical Period' can be broken down into two words: 'EPOCH' and 'ERA'. An EPOCH is a period of time in history that is marked by significant events or changes, while an ERA is a longer period of time that is divided into smaller parts. Both terms are used to describe a particular period in history, such as the Renaissance or the Industrial Revolution. Generally, an EPOCH is shorter than an ERA, but both terms are used to refer to a period of time that is considered to be important in history.