Files Aka Nautilus.
Files Aka Nautilus is very simple and easy to use. However in LMDE5 Nemo is the standard file manager.
The file manager is designed to fit the Gnome desktop design and behaviour, giving the user a simple way to navigate and manage its files.
Nautilus was the flagship product of the now-defunct Eazel Inc and was released under the terms of the GNU Lesser General Public License.
It is free and open-source software.
Nautilus was first released in 2001 and development has continued ever since.
How to install using a terminal window:
sudo apt-get install nautilus
Press Enter, done.