The term "chronology" comes from the Greek words "chronos" (time) and "logos" (study). It is a relatively new science, with its origins in the 17th century. Before this time, there was no systematic way of measuring time or arranging events in their proper order.
Chronology is based on the assumption that time is linear and that events can be placed on a single timeline. This assumption is not always valid, however, as there are some events that are difficult to place on a single timeline. For example, the beginning of the universe is an event that is difficult to place on a timeline, as there is no clear starting point.
Despite these challenges, chronology is a powerful tool for understanding history. It allows historians to see how events are related to each other and to create a coherent narrative of the past.