As I was browsing looking for something difference bout anything, I found this article. by Dr. dig..
What is B.C : BC is an abbreviation that stands for Before Christ this event is used by worldwide archaeologists to indicated that an event that took place or occurred before the birth of Jesus Christ.
What is A.D : DC on the other hand is an abbreviation came from a Latin word which stands for Anno Domini. This is used to indicated where and event that took place after the birth of Jesus Christ or Event that happened in the year of our Lord.
This system of dating has been used for many years by Western archaeologists. however, with a growing understanding and awareness that not all archaeologists are Christians, some archaeologists prefer to use the terms: Before the Common Era (B.C.E.) and the Common Era (C.E.), which are exactly the same as B.C. and A.D. but have nothing to do with Christianity.
So in conclusion : if one day or even presently when we all found these abbreviation was now know that
Before Common Era (BCE) also knows as Before Christ (B.C.) while Common Era (C.E) also known as An no Domini (A.D.)