This should help.
http://store.apple.com/us/mac/compare
There are 3 options. Macbook, Air, and Pro.
If you are used to, or spend a lot of time looking at a screen, the higher (retina) resolution screen on the Pro is amazing, and expensive.
The current Air is freakishly thin and light. So thin, that they can't fit a std USB port. If you want to plug in loads of usb devices, the Air will limit you. The USB-C port is the only ubs port and it doubles at the charge port. So unless you buy an adapter, you can only plug a single item in at a time.
Typical laptop users will freak out about this, but with ~12 hours battery, it's not essential to have it charging constantly.
A pro on the other hand is more like a traditional laptop.