[ale] [OT]How does Android pull off url "spoofing"?

[Jim Lynch]

The only way I've been able to get files transferred from my wife's 
Linux box to/from her Android phone is by using AirDroid.  gMTP just 
doesn't work.  Anyway when she brings up the app on the droid, it 
instructs her to go to www.airdroid.com (might not be perfectly 
accurate, I don't recall the exact url for sure) and lo and behold when 
she goes to that url, she's connected to her phone, which is connected 
via wifi to the router.  How in the heck does Chrome or FF know to 
resolve that url to 192.168.2.91:8000 or whatever it is?

I thought I understood networking but that's stumped me.

Thanks for any insight.

Jim.