Just a matter of using the correct words :
A folder is designed to contains other folders and files.
The way data is organized in the "virtual world" is not so different from the real world. Files (documents) are placed in folders, each of them having a name so we can differenciate them. Each folder can contains files and other folders, as simple as that!
Actions on files
Here is how to do these essential actions on files and folders. If some terms such as "drag and drop" are unknown to you, see the mouse
and the keyboard