Is there any difference between iPad Air part numbers? Like
zp/e – for different countries.
I want buy a new iPad Air and I stock between different part numbers.
The difference is localization. For iPad Air, it only means that you will get translated documentation. So it's OK to get it from another country like the Philippines.
Warranty is worldwide. The software language you will choose on first use, and you can change it later.
The only real difference is for products with keyboards (iMac, MacBook, etc), obviously then it will influence your keyboard layout (QWERTY, AZERTY etc.).
Yes those are Model Regions, You can check the numbers here
As the site states:
It is not possible to see to what carrier the phone is locked (or not) by just looking at the model number, but it gives you an idea where the phone was intended to be sold.
Summarized for you: