The shift key on
keyboards got its name after the Remington #2
typewriter.
The first typewriter, built in 1868, only typed in capital letters. The second-generation model, in 1878, allowed UPPERCASE and lowercase letters. The trick was that each typebar (the piece that would swing up and hit the page with the letter) now had an Uppercase and lowercase letter on it. Pressing the "Shift" key would actually shift the typebars in order to shift the Uppercase keys into position.
Of course, the modern typewriters and word processors and electronic devices no longer need to shift mechanically, but the name stuck, and carried over to computer use, as the QWERTY keyboard layout was used to mimic a conventional typewriter.