It's a stem, dammit!

This, my dear friends, is a bike part called the stem. So please do not call it a freakin' handlepost. No, it's not a headpost either.

Go to this online shop and this one and try to see if they sell a bike part called handlepost or a headpost. You can try looking for it in Wikipedia, if you like.

Only this "shop" calls it as such.