Gap creationism

Gap Creationism is a belief about how the world was created. It says that when the Bible talks about "days" in the book of Genesis, it doesn't mean 24-hour days, but instead each day could have been millions of years long. This means that God created the world in a series of long periods and built it up over time, with gaps of thousands of years in between each period. This way of looking at the Bible explains why there are fossils in the ground - they weren't created but the result of long periods of time.