Nullable Reference Types 1 - What Are They For?

In 2019 (C# 8.0) Microsoft introduced a feature that has generated a lot of confusion, debate and outright dissent. I'm talking about Nullable Reference Types. In this video series, I want to really dig into this feature, understand it and help you as a programmer decide if and how you want to use it. Let's start with the obvious questions: what are Nullable Reference Types for? What do they do? What problem do they solve?