Backup and Sync from Google - Icon Explanation

Question

I just started using Backup and Sync from Google on my Windows 10 laptop.

It seems very useful so far, but I could not find an explanation for the icons.

When I open Windows Explorer and open my "backup / sync" folder, the icon is different, depending on which settings I have enabled.

Could someone document here what exactly the different icons are indicating?

Here are a few of the examples I could find after cropping and uploading them:

cloud, slash, checkmark

cloud, slash

folder, checkmark

folder, logo

logo

logo, checkmark

I wish that there was easy to find documentation on the Google Drive icons.

Maybe someone can post here all of the possibilities to help others as well.

Thanks.