What does maximum operating altitude mean?

Because I read on apple.com that she maximum operating altitude for a MacBook Pro and iPhones, etc was 10, 000 ft. How do people still use them in planes?

I seriously hope you are trolling.

Why do they work in planes at high altitudes. Let's see.

For the same reason you breathe in planes at high altitude?

How do you think you can breathe in a plane at 30, 000 feet? Because the air is pressurized so that passengers and crew can breathe it. The plane is also heated so that passenger's don't freeze, as it's incredibly cold at 30, 000 feet.

Because planes have pressureized cabins.