DESC: Traditionally notebooks are made from multiple parts. Every MacBook starts its life as a single block of aluminum, which is precisely machined into the basic unibody design. Another pass and the unibody takes shape. Another, and the integrated keyboard emerges. When you pick up a MacBook you immediately notice the entire enclosure is thinner and lighter. And it feels strong and durable--perfect for life inside (and outside) your briefcase or backpack.