In Ubuntu 18.04 LTS, there is a customized version of the Gnome desktop. Ubuntu has done some changes on its 18.04 release to make it look like Unity desktop. However, some users might not like these changes. For them, there is a simple and minimized Gnome desktop environment also known as Vanilla desktop that they configure it in the way they want.
In this article, we will learn how to install vanilla GNOME on Ubuntu. In Vanilla desktop, you will notice:
- Missing Ubuntu Dock
- Missing app indicator support
- Missing minimize and maximize button on App windows
- Adwaita GTK and icon theme
- Cantarell font
We will use Ubuntu 18.04 LTS for describing the procedure mentioned in this article.
Installing Vanilla GNOME
To get started with the installation, Press Ctrl+Alt+T to launch the Terminal application in Ubuntu. Then type the following command in the Terminal:
$ sudo apt-get update
Then to install the basic Gnome desktop environment also known as Vanilla desktop, enter the following command in Terminal:
$ sudo apt install gnome-session
Wait for a while until the installation completes.
If you also want to get the GDM3 login screen of Gnome desktop, run the following command in Terminal:
$ sudo update-alternatives --config gdm3.css
Then you will be asked to enter your choice. Select number 1 that is “gnome-shell.css” and press enter. It is the default GNOME. After you select this option, the GDM login screen will change to the default theme.
Now you will need to restart your system. After the restart, you will see a new login screen. Select the user and then click on the gear icon and select Gnome on Xorg and log in with your same old credentials. 
Once you log in, you will see the Vanilla desktop without the dock, app indicators sidebar, and Ubuntu welcome screen. However, you will notice the wallpapers and color scheme has not changed. Now you can customize your Vanilla desktop in the way you want.
Here is the default view of the vanilla desktop after login:
To launch the Search screen, click on the Activities in the top left corner of the screen. You will see the most often used applications listed on the left.
That is how you can install the Vanilla Gnome shell on your Ubuntu 18.04 LTS. However, if you want to shift back towards Ubuntu’s Gnome desktop customized theme, you can switch back on the login screen.