Green Bars in Visual Studio 2010

Question

I am wondering what these greens things are in Visual Studio 2010. What are they for? They look pretty random but of course they have to have some meaning. Can any one tell me?

At first glance they don't mean any thing to me.

Picture 1:

Picture 2:

Edit:

They show saved changed content during the document open. Once you close the document they disappear.

Answer 1

This is edited lines of text after last save

or/and

Lines of code edited by Edit->Advanced->Format Document. It formats code (spaces, line breaks, etc) corresponding VS settings for current file's language

Answer 2

Those indicate where the source code has been changed.

Answer 3

They show lines that you have changed.

See here for more details and a table showing what the different colours mean:

+-----------+------------------------------+-------------------------+
| Marker    |     Different from           |    Different from file  |
|  colour   |       file saved on disk?    |      that was opened?   |
+-----------+------------------------------+-------------------------+
| Nothing   |        No                    |       No                |
| Yellow    |        Yes                   |       Yes               |
| Green     |        No                    |       Yes               |
| Orange    |        Yes                   |       No                |
+-----------+------------------------------+-------------------------+

Answer 4

Yellow - source code that has been changed since you opened the file, and that hasn't been saved.

Green - source code that has been changed since you opened the file, and that has been saved.