Plane travel within Schengen zones

There is no passport control, but there is a passport/ID check upon boarding (to check that you are the ticket holder).
Otherwise the experience varies from airport to airport... Small regional airports are a breeze (I often go to a French town of 80,000 whose 3-flight-a-day airport is so small that arriving 20 minutes before scheduled departure is fine!), larger airports do come with check-in and security lines and require you to be there 90 minutes before departure, or even 2 hours if you have luggage to check.

Travel-wise Schengen zone is like a large country. If you are in - you are in. No permanent extra checks of cross-border traffic, only random checks.

I fly within Schengen frequently. Very similar to. Domestic US flight. No passport control at all, just security, which is very civilized. I’ve often flown from city to city without a single person checking my ID. Not even the folks at the gate.

I would agree, the process and expectations are the same as flying domestic within the US, however a couple things to add...

• While we have the TSA, each Country handles it's own security, coordinated by some EU standards. Do not assume items that are "OK" for TSA will be accepted in Europe. As an example, for sharp objects, EU uses the guideline "no Items with a Sharp Point or Sharp Edge"; so corkscrews are a no-go, in the US corkscrews are OK. In both countries though, interpretation is at the discretion of the agent.
• In the US for Domestic Flights, multiple types of ID are accepted through Security. In Europe, only your Passport (at least for US Citizens) is accepted.
• Certainly with the budget airlines, but in my experience with all, the Airlines are much more strict about the size, weight, and number of items you carry on; and charge you for any overage.

You will see residents of EU countries showing their national identity cards for boarding or security instead of a passport.

You will see residents of EU countries showing their national identity cards for boarding or security

But non-EU/Schengen citizens must show a passport as ID.

As an example, for sharp objects, EU uses the guideline "no Items with a Sharp Point or Sharp Edge"; so corkscrews are a no-go, in the US corkscrews are OK. In both countries though, interpretation is at the discretion of the agent.

Well, that's interesting. I didn't realize, and have flown intra-Schengen multiple times with my picnic corkscrew. I guess that's another similarity to US security: they don't catch everything!

You will see residents of EU countries showing their national identity cards for boarding or security instead of a passport.

Yes, that is why I qualified it to indicate US citizens. In previous discussions people who have lost passports are amazed that their US Drivers License, a photocopy of a passport, or just vouching by their Spouse is not sufficient to go through Security.

Of course in the US, after October of 2020, your Drivers License may not work unless you have renewed and submitted additional information to meet the requirements of Real ID, which is a form of National ID Standards.