Originally Posted by Jani

from wiki - The QWERTY layout is certainly far from the most efficient, since it requires a touch-typist to move his or her fingers between rows to type the most common letters. A popular story suggests that it was used for early typewriters because it was inefficient; it slowed a typist down so as to reduce the frequency of the typewriter's typebars from wedging together and jamming the machine. A more likely explanation is that the QWERTY arrangement was designed to reduce the likelihood of internal clashing by placing commonly used combinations of letters farther away from each other inside the machine. This allowed the user to actually type faster without jamming. Unfortunately, no definitive explanation for the QWERTY keyboard has been found, and typewriter aficionados continue to debate the issue.