Different toilets from different countries

Hello,
I am wondering-
Why Are the American toilets different from the European toilets?
Are all American toilets uses siphon flushing, as opposed to the europeans? Why is that?
Are all American toilets have an underneath drainage, as opposed to the back drainage of the europeans? And why is that?
Are there any other differences?
And what about the rest of the world? Australia, Asia, Africa, South America, The middle East?
Thanks,
Saar

1. Construction in the US is different than many places in Europe. This question is almost a rhetorical one.
2. See the answer above. In many places in Europe there isn't space below the toilet for plumbing which leads to rear drainage designs.
3. Most are, see the answer above.
4. The US generally has more modern drainage systems.
5. A lot of places in Asia, Africa and the Middle East use squatter toilets. Bidets are also more popular in Europe and S. America, both things are generally unfamiliar to US residents.

I've seen lots of "underneath drainage" toilets in Europe...

The main difference I noticed, is they make the trap lower, which means less water in the bowl. That leads to... well, let's just say that "smell containment" is better on American toilets. Also... hopefully not getting too graphic, but... more smears on the side of the bowl, in Europe.

I lived in the UK for 35 years and have got to say, from a clogging perspective, the UK toilets are miles better than the US ones. I can't remember ever a time when me or my family members ever had to reach for the plunger. Nobody I knew even owned a plunger! I've always wondered what's different about the UK ones that makes them so good.

I must admit, I don't remember seeing plungers by toilets in Australia when I was growing up... but I also remember pulling the chain in some places, maybe putting the tank up 6 feet would fix those two piece thrones that have a MAP < 500