CE and BCE are alternatives to AD and BC.
The term AD is an abbreviation of the Latin words ‘Anno Domini’, often translated ‘in the year of (our) Lord’. It refers to the traditional dating of Jesus‘ birth (1 AD). Its counterpart BC stands for ‘before Christ‘, i.e., before Jesus’ birth. The terms CE (Common Era) and BCE (before the Common Era) are commonly used by scholars of religion and the Bible. These do not assume that Jesus is the writer or reader’s ‘Lord’ and means that all writers and readers are included regardless of their personal beliefs.