the latest macbook air has NO MOVING PARTS! the hard drive has been replaced by on board memory, like soldered on the board. MUCH less heat. MUCH less battery usage. Programs load sooooooooo fast cause they don't have to be read in from a spinning drive. Boots up in 5 seconds. shuts down in two seconds. Photoshop loads in 4 seconds compared to 15 seconds on my Macbook Pro, and like 40 seconds on last year's macbook air. Fastest machine i ever had.