What is bc and ad?

BC= Before Christ. Everything before the birth of Christ is recorded with a BC after it. For example, Stonehenge was built in 3500 BC. This means Stonehenge was built 3500 years before the birth of Christ

AD= Anno Domini. This is latin for After Christ. All dates after the birth of Christ are recorded with an AD after it. For example, this is the year 2011 AD. This means this year is 2011 years after the birth of Christ