The "Focused" tab is where all of your high-priority emails will be found, while everything else will be in the "Other" tab. Outlook will learn from your behavior over time and sort your mail accordingly.
That's a non-sequitur. High priority emails are those with a Priority:urgent header. There's nothing to learn, it's a simple, straightforward rule, which has been done for decades by any decent MUA. If they're doing something different, they shouldn't call it "priority.'