htop - Monitor Your Linux System.
A text-mode application (for console or X terminals) and requires ncurses.
htop is an interactive top replacement that runs in the terminal.
htop is an easy to understand monitor of system processes, running in a terminal window on your Debian Linux system, like the usage of CPU, Memory, Swap and so on.
htop - monitor Linux system processes:
You can use your up and down arrow keys to select a process and if you like just press F9 to kill a process.
The F7 and F8 keys can be used to change priorities, of course you need to be logged in as "root", to do so.
How to install via a terminal window:
sudo apt-get install htop