The MacBook is a brand of notebook computers manufactured by Apple Inc. from early 2006 to late 2011. It replaced the iBook series and 12-inch PowerBook series of notebooks as a part of the Apple –Intel transition from PowerPC. Positioned as the low end of the MacBook family, below the premium ultra-portable MacBook Air and the powerful MacBook Pro, the Apple MacBook was aimed at the consumer and education markets. It was the best-selling Macintosh in history, and according to the sales-research organization NPD Group in October 2008, the mid-range model of the MacBook was the single best-selling laptop of any brand in US retail stores for the preceding five months.