Let's expand our diagram to include the right side of Windows Explorer...

As you can see, I clicked on the plus sign to the left of the "Acrobat3" folder, and it showed me a sub-folder named "Reader". "Reader" also has its own sub-folders, as the plus sign to the left of it shows. Windows Explorer shows the sub-folders of "Acrobat3" and the files within on the right side. Readme.txt is the only file contained in the "Acrobat3" folder.