[PAR] [TLE] MacBook [SEP] There have been four separate designs of the MacBook.  The original model used a combination of polycarbonate and fiberglass casing which was modeled after the iBook G4.  The second type was introduced in October 2008 alongside the 15-inch MacBook Pro; the MacBook shared the more expensive laptop's unibody aluminum casing, but omitted FireWire.  A third design, introduced in late 2009, had a polycarbonate unibody casing. [PAR] [TLE] PowerBook [SEP] The PowerBook (known as Macintosh PowerBook before 1997) was a line of Macintosh laptop computers that was designed, manufactured and sold by Apple Computer, Inc. from 1991 to 2006.  During its lifetime, the PowerBook went through several major revisions and redesigns, often being the first to incorporate features that would later become standard in competing laptops.  The PowerBook line was targeted at the professional market, and received numerous awards, especially in the second half of its life, such as the 2001 Industrial Design Excellence Awards "Gold" status, and Engadget's 2005 "Laptop of the Year".  In 1999, the line was supplemented by the consumer iBook range.  The PowerBook and iBook lines were discontinued and replaced by the MacBook Pro and MacBook families respectively by 2006.
[PAR] [TLE] MacBook [ SEP ] There have been four separate designs of the MacBook . The original model used a combination of polycarbonate and fiberglass casing which was modeled after the iBook G4 . The second type was introduced in October 2008 alongside the 15-inch MacBook Pro ; the MacBook shared the more expensive laptop 's unibody aluminum casing , but omitted FireWire . A third design , introduced in late 2009 , had a polycarbonate unibody casing . [PAR] [TLE] PowerBook [ SEP ] The PowerBook ( known as Macintosh PowerBook before 1997 ) was a line of Macintosh laptop computers that was designed , manufactured and sold by Apple Computer , Inc. from 1991 to 2006 . During its lifetime , the PowerBook went through several major revisions and redesigns , often being the first to incorporate features that would later become standard in competing laptops . The PowerBook line was targeted at the professional market , and received numerous awards , especially in the second half of its life , such as the 2001 Industrial Design Excellence Awards " Gold " status , and Engadget 's 2005 " Laptop of the Year " . In 1999 , the line was supplemented by the consumer iBook range . The PowerBook and iBook lines were discontinued and replaced by the MacBook Pro and MacBook families respectively by 2006 .
What had four separate designs and replaced The PowerBook and iBook lines?
What had four separate designs and replaced The PowerBook and iBook lines ?
MacBook
MacBook