What does sudo apt-get update command do on Ubuntu/Debian?


Originally published at: https://www.cyberciti.biz/faq/what-does-sudo-apt-get-update-command-do-on-ubuntu-debian/

I am a new Ubuntu / Debian Linux user. I wanted to know what does sudo apt-get update command does? What does it update and how do I tell apt-get to update? What does “sudo apt-get update” do on my Debian Linux server? What is the difference between “sudo apt-get update” and “sudo apt-get upgrade”?