See this Apple page for details
"I’m a little surprised to see the MacBook dropped completely, but the Air, though bigger, is a much more capable machine. Overall, it is a tremendous simplification of the entire MacBook lineup, and that’s a good thing. Retina Air and two sizes of MacBook Pro — hard to see how it could get any simpler. Other than the increase in size of the “smallest” MacBook, the only knock against today’s revamp is that the starting price (for those other than college students) has jumped from $1000 to $1100.Apple Revamps MacBook Lineup | Daring Fireball
UPDATE: A few other observations:
- Apple isn’t making a point of it, but these new MacBooks both have the new third-generation butterfly keyboards.
- According to Student Monitor, MacBooks have 60 percent market share among college students. That’s impressive period, but downright bananas for those of us who remember where Macs were market-share-wise 20 years ago.
- Apple’s back-to-school promotion saves you up to $200 and includes a pair of Beats Studio 3 wireless headphones, which retail for $300. That’s a great deal."