If you need to run few commands or a script at boot, just for one time to set some settings or to mount few folders or to set iptables rules or set processor power saving and settings ..etc, you can do so using crontab.
If you run a computer or a laptop remotely, you may need to shutdown its monitor, so that if you connect to it using VNC, the mouse and keyboard do not result in the screen automatically reopening and showing everything done on that computer.
After doing a clean installation, trying to use the command to install something
apt-get install byobu
I get error:
E: Unable to locate package byobu
I discovered that the default /etc/apt/sources.list file does not have enough sources to get allot of the basic packages.