In 2004 apple was thinking about switching to a different CPU to build they’re computers because the current CPU(power pc) got to hot that’s why no iBook G5 exist. So in MacWorld 2006 Steve Jobs came up to stage and announced that the new apple computers would run on Intel instead of power pc. That day apple announced the iMac Intel (not G5), the MacBook and MacBook Pro. You should also know that the G3, G4 naming pattern was dropped because the computers no longer run on power pc(power pc G3, G4), the power book was rebranded to the MacBook Pro, and the iBook was rebranded to MacBook. Please visit eddy4ai.com and donate, thanks, Edward.