XFCE is a simple and lightweight Linux desktop.

XFCE is a stable and lightweight desktop that runs on Linux and other systems. It may be peferrable for those who want a traditional style desktop instead of the modern Unitity desktop that comes with Ubuntu 16.04.

Installing XFCE is as simple as running the following two commands in a terminal:

sudo apt update

sudo apt install xfce4

That's it. Then you'll need to log out of your current desktop session and log in again, but choose "Xfce Session" at the login screen.