Ubuntu Linux is very popular nowadays for DevOps engineers when always setup the OS in the servers, then there are some basic commands on Ubuntu OS as shown below:
When administrators can not have access to modify specific files on the Ubuntu OS, there is a command-line argument that run programs with administrative priveleges as superuser.
One of the most important command-line argument is apt-get to install, update or upgrade and remove any package installed in the Ubuntu OS. For example, administrator can use sudo apt-get update to run a fresh install on Ubuntu Linux OS. Another command-line argument is sudo apt-get upgrade [package_name] in order to upgrade installed packages. The third command-line argument to install a program is sudo apt-get install [package_name] and replace package_name with your desired package that you wish to install it on the OS such as Google Chrome, Mozilla Firefox programs, etc.