Command is an instruction given by a user to perform a particular tasks in linux. Commands are generally used by typing them in at command line interface and pressing Enter key, which passes it to the shell. Shell is a program that reads command and execute it.
The main advantage of vim is , you have lot of option to edit your file. There are lot of command option in vim editors. Many options are also available in other editors. Uses of editors depend on users choices.
SAR (System Activity Report) is an very important unix monitoring command used to report performance of various Linux subsystem in real time. Using SAR you can generate report of your system performance statics on regular basis and store it for analysis .
There are lot of network monitoring tools available in market today. We use network monitoring tools to monitor our network. If any network component became slow or failed , network monitoring tools notify us about that problem (via email, sms or other alarm).
The main advantage of linux is , you can work on both graphical and through command line. Linux distribution have long been used as Server operating system. But the popularity of Linux on standard desktop computers and laptops has been increasing over the years.