Answer:
Writers Talk About Writing
Ctrl+Shift+Return: Keys to Your Computer
By Mike PopeOctober 15, 2012
Your computer's keyboard has around 110 keys by which you can make your wishes known to the machine. Most of these have obvious labels: if you press the A key, the letter A appears on the screen. Some are less obvious, though — the Shift key and the mysterious Ctrl key — and in this article I'll explore why they're named what they're named.
Long before computers, many practical issues about using a machine to write had already been worked out for the typewriter. If you've never used a typewriter, you might be interested in this video that shows one in action.