web UI uses "apt repo" and "deb repo" interchangably
If you look at the web UI for content views and click on the "apt repo" tab, you'll see that it's called "apt repo" on the tab, and "deb repo" in the tab's pane. There are references to both in various places in Katello.
We should standardize on either "apt repo" or "deb repo". I would vote for "apt repo" since we already use "yum repo" consistently and I never hear users say "rpm repo". However I'm not as familiar with apt so I don't know if people usually say "apt repo" or "deb repo".