(Most of the shortcuts are the same on a Mac, except you use the CMD key instead of the CTRL key.) When you want to print something, press Ctrl+P. Press Ctrl+F to find a word in a document or web page. There are dozens of them, from pressing Ctrl+A to select everything in a window to pressing Ctrl+B to make selected text bold. A single, quick shortcut can accomplish the same thing as moving your mouse across the screen and clicking through several menus or hunting down buttons. To perform a keyboard shortcut, you press two, three or sometimes four keyboard keys at once.
But telling them what to do is often a slow process. The great thing about computers is that they can work much faster than you can.