Don’t ask. It makes things more exciting that way.

coming from arch that’s terrifying

The god of penguins will punish you if you do not follow his will.

Tux has spoken.

It’s not necessarily required but it is strongly suggested in case the package you are installing requires the latest version of a dependency.

It updates the package lists APT uses. You don’t have to run update before installing. But you could be installing the previous version of the application. For instance if you never run update, the upgrade command won’t do anything.

Edit: spelling