What is the difference between a directory and folder?
A directory and folder are the same thing. The Windows folder on the C: drive of Windows is the same thing as C:\Windows in MS-DOS. Therefore, there really is no difference between the two, other than the names.
However, when referring to a command line interface such as MS-DOS or Linux, it's more correct to say directory instead of folder. In a GUI (graphical user interface), such as Windows, it's more appropriate to say folder instead of directory. An easy way to remember the difference between the two is that when you're viewing folders and files in Windows, they have pictures (shown in the image to the right). In a command line, there are no pictures of folders.