Here is the description of abra from it's git repository: abra is a command-line tool for managing your own Co-op Cloud. It can provision new servers, create applications, deploy them, run backup and restore operations and a whole lot of other things. It is the go-to tool for day-to-day operations when managing a Co-op Cloud instance. Abra is undergoing a rewrite and so it is deprecated. It's still in use on a daily basis, but it will be replaced.
Note that Linux gives you a warning about having "received the usual lecture from the local System Administrator." This is because the `sudo` command gives the command you type (`apt-get update` in this case) "root" privileges. Using `sudo` is similar to when you are doing something in Windows and the `User Account Control` window pops up and asks you to confirm before continuing with an action requiring elevated privileges. Whenever you type `sudo` in a Linux system, be aware you are using elevated system privileges.