QWERTY

The QWERTY layout is not the most efficient layout possible, 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 designed and used for early typewriters exactly because it was so inefficient; it slowed a typist down so as to reduce the frequency of the typewriter's typebars wedging together and jamming the machine. Another story is that the QWERTY layout allowed early typewriter salesmen to impress their customers by being able to easily type out the example word "typewriter" without having learnt the full keyboard layout, because "typewriter" can be spelled purely on the top row of the keyboard. The most likely explanation is that the QWERTY arrangement was designed to reduce the likelihood of internal clashing by placing commonly used combinations of letters farther from each other inside the machine.This allowed the user to type faster without jamming. Unfortunately, no definitive explanation for the QWERTY keyboard has been found, and typewriter aficionados continue to debate the issue.