Ubuntu server comes default with a Command line interface. Of course we can install GUI in Ubuntu Server if we find command line troublesome. Here are the steps.
First navigate to the “etc/apt” directory and open a file named “sources.list.d” using the command “vi sources.list.d”.
Then check whether software from “universe” ad “multiverse” repositories are allowed.
Then type the command “sudo apt-get update” to update all repositories.
After updating is finished, type the command “sudo apt-get upgrade”.
Then type the command “sudo apt-get install ubuntu-desktop”. It will take some time to finish all the processes.
After the installation is finished, restart the server to see your GUI interface.