DIfference between iBook and G5, iMac

[The Giver]

What is the difference between an iBook G4, New G5's, and the iMac?

 

[ApplejustWorks]

G5 is the worlds fastest personal computer, the iMac is the middle level G4 desktop, and the iBook is the lowend NoteBook line

 

[Chamorro]

What is the difference between an iBook G4, New G5's, and the iMac?

G5 = Newest technology processor, higherst-power and expandability.
iMac = All-in-one design w/ good power, should fit the needs of the majority of customers, but limited internal expandability.
iBook G4 = Portable iMac.

 

[Graphite]

G5, 64Bit processing. Which is hella quick at a speed of 1.8 to 2.0ghz,
G4 iMac, Great machine, nice LCD monitor, quick enough to complete most tasks.
G4 iBook, Light, powerful, smooth transitioning, will be one of the quickest if not the quickest portable laptop your fingers have touched if your usta PCs.

All of them are great machines.. and so you ask what is the true deciding factor in the speed?
RAM
RAM
RAM
RAM
RAM