Your external address is the one you use to surf the internet with.
It should be something like: 77.256.258.77 or 125.77.126.122, etc. It can be any combinations of numbers.
It WON'T be 192.168.1.1 etc, as that is your internal LAN address only other computers IN YOUR house can see. If your making a server for the other computers in your house it would be the same set of numbers as your router address except for the last set.
Macbook air
Apple has a feature called Continuity that gives your MacBook Air the ability to make a call to a mobile phone. It does require a MacBook Air or Pro with the Yosemite OS, and the iPhone would need to be iOS 8.
The MacBook Air was probably slightly below the MacBook. As of 2012 they no longer make a MacBook as the Air took it's place. It's a moot point now I guess.
No, the Macbook Air does not break easily.
Macbook Air.
I do not believe so, I have an 11" Macbook Air and tried to make Applications, iPhone Apps, and Games. None of them worked for me, probably cause I have 10.8.2 instead of 10.7.5
The MacBook Pro cases are much larger and sturdier the the MacBook Air cases.
The camera built into current Macs (including the iMac, the Macbook, the Macbook Air, and the Macbook Pro) is known as the iSight
MacBook Pro is the best you can get
For app development for both the design and the coding aspect, the Macbook Air has really nailed it if you do compare Macbook Air with Macbook Pro.
Apple makes the MacBook Air line of laptop computers.
The MacBook Air can access the Internet by joining a wireless network.