How to deactivate or disable a user account in Ubuntu 20.04 LTS

If you want to disable any user to prevent that the user logs into his/her account on Ubuntu or lock the user?s account so he/she won?t be able to log in and access the privileged rights, you can do it in three ways through command line input (CLI). This article will explain and demonstrate these 3 ways through which you can perform the specified task.