Be careful with -R ; it will also make every file executable, which is rarely what you want.
This specific permission set is the "Goldilocks" setting for most public folders and web servers. drwxr-xr-x
For directories, "execute" means "search" or "traverse." Without x on a directory, you cannot access any files inside it, even if you have r permission. Be careful with -R ; it will also
You cannot cd into a regular file. The d immediately tells you that Documents is a folder you can enter. Be careful with -R
chmod -R 755 mydirectory