And I'd assume they're called "X ring" binders, as opposed to just binders, because "binder" is a fairly generic term.
As for the number of rings: first mover advantage and network effects.
Paper is produced with three rings. Teachers buy three ring hole punches. Soon binder manufacturers target the most common standard. All other standards die off.
I have seen and used four ring binders in America. But three ring was the phrase that jumped out in my head.
You have to try it. It is such a joy. The pages turn like butter and never tear out. You can lift the entire binder by a single page. The paper size feels much
more human-scale. I exclusively use J-Binders for my notes.
I'd love to try one of those. Three-ring binders are a chore because the holes are so easy to tear with daily use. Sure, they sell stickers that you put over the teared holes to repair them, but why not redesign the binders in the first place?
In The Netherlands, in schools 23-ring-binders are quite heavily used. In office environments it is mostly 2- or 4. The nice thing is that they are compatible: if you have 23-ring-paper or 4-ring it will fit in 2 or 4 ring binders. This does not work the other way around for obvious reasons.
As for the number of rings: first mover advantage and network effects.
Paper is produced with three rings. Teachers buy three ring hole punches. Soon binder manufacturers target the most common standard. All other standards die off.
I have seen and used four ring binders in America. But three ring was the phrase that jumped out in my head.