htop is a very competent interactive process viewer for the shell, providing all the functionality - and more - that the top utility does, in an easier and more intuitive way. htop provides easy-to-use menus for most operations and also has support for using a mouse.
htop is an easier to use and friendlier version of top. While it hasnít as much time behind it and therefore is less tested, it seems to work very well both locally and over SSH, and itís well worth taking it for a spin. Itís just one of those small utilities that makes life a bit easier.
Install htop in debian
#apt-get install htop
This will complete the installation.Now if you want to check this application just type the following command from your terminal
You should see the following screen
If you want to know about the more available option check htop man page
Comparison between htop and top
In 'htop' you can scroll the list vertically and horizontally to see all processes and complete command lines.
In 'top' you are subject to a delay for each unassigned key you press (especially annoying when multi-key escape sequences are triggered by accident).
'htop' starts faster ('top' seems to collect data for a while before displaying anything).
In 'htop' you don't need to type the process number to kill a process, in 'top' you do.
In 'htop' you don't need to type the process number or the priority value to renice a process, in 'top' you do.