Typewriters are machines created to allow individuals to create written documents by simply pushing upon keys. The first typewriter was created in 1868 by C.L. Sholes.
Typing classes mushroomed at the end of the 19th Century, and this helped many women to enter paid work for the first time. By 1901, Britain had 166,000 female clerks, up from 2,000 half a century before. 
The original typewriters were manual, but later became electric. A piece of paper was usually inserted into the machine and the depressing of a key would cause a metal hand with that key shape to push forward and strike the page, then the paper would move forward for the next key displacement.
Human capacity to type was faster than the machine and its mechanical parts could handle, so the odd key placement common on typewriters was invented to slow down typing speed.
"I have never had an accident where I have pressed a button and accidentally sent seven chapters into cyberspace, never to be seen again. And have you ever tried to hack into my typewriter? It is very secure." 
The New American Desk Encyclopedia, Penguin Group, 1989