I think all of us noticed the colors in the left margin of the editor of Visual Studio, but do you know what these colors mean? To be honest… I know that these colors are already there for more than five years. And I know that they have something to do with tracking changes in my code. But I never asked myself what they actually mean. This is quite strange because for at least five days a week, a couple of hours per day, I’m coding in the Visual Studio editor. I’ve seen wittingly or unwittingly these colored markers many and many times.