I will discuss a few desktop environments for Ubuntu and how to install them.

1.XFCE:-

XFCE should please the majority of users, especially ones who prefer a lean, fast, and highly flexible desktop. To install XFCE on Ubuntu, follow these steps:-

- Open a terminal window.

- Issue the following command: 

sudo apt-get install xubuntu-desktop

- Type your sudo password and hit Enter.

- Accept any dependencies and allow the installation to complete.

- Log out and log in, choosing your new XFCE desktop.

Congrats you now have XFCE desktop environment.


2.KDE:-

KDE is not nearly as lightweight as XFCE, but it is powerful and offers a number of features other desktops do not. Here's how to install KDE on Ubuntu:-

- Open a terminal window.

- Issue the following command: 

sudo apt-get install kubuntu-desktop

- Type your sudo password and hit Enter.

- Accept any dependencies and allow the installation to complete.

- Log out and log in, choosing your new KDE desktop.

Congrats you now have KDE desktop environment.


3.Classic GNOME:-

With Classic GNOME, no installation is necessary. You log out and then, after selecting the user to log in with, select Ubuntu Classic from the desktop drop-down menu. Now, enter your user password and log in. You should be greeted with the familiar GNOME goodness.