Is there a difference between BC & AD? Yes, BC refers to the time before Jesus was born, & AD refers to the time after Jesus was born. Currently we are in the year 2024 AD, meaning that it is 2024 years since Jesus was born.
CE is an alternative to the AD system used by Christians but the numbering is the same: the year 2024 CE is equally AD 2024 (but usually we just say "the year is 2024"). AD is an abbreviation of the Latin: anno domini, lit.