Biblical Series: Question 1: Why are there two Genealogy lists that conflict with each other in Genesis, and which one is the real one?

In my attempts to understand the Bible I want to get answers from devout Christians and Jews if there are any, on the many questions I have. I have to wonder why they would give two different ancestry lists here that, while some are similar names, some may be different ways to say these names, there are clearly some errors here.