Ubuntu has been providing very good GUI interface to manage applications and system, such as installation, uninstall the programs, networking, etc. However, as other linux users, we can not be much use in the command line like DOS in Microsoft Windows, to help manage system.
For a newbie in linux, ubuntu specifically, we should at least understand a few basic commands that are often used to perform system administration. In Ubuntu, if we want to manage system in terminal, always use 'sudo' command. Sudo is Super User Do, where the user hwo have sudo privilleges can manage the system without login as root user. For example :
$ sudo