Before the Common Era, often abbreviated as BCE, is a term used to denote the period of time before the start of the modern Gregorian calendar, which begins with the year 1 AD. However, there are other phrases that can be used to refer to the same period. These include Before Christ (BC), Anno Mundi (AM), Before Present (BP), and Prehistory. While each of these terms has a slightly different connotation and is used in different academic contexts, they all generally refer to the same period of time. Regardless of which term is used, they all provide a way for us to understand and contextualize the rich history of human civilization.