Today, we're going to discuss the critical role graphical user interfaces, or GUIs played in the adoption of computers. Before the mid 1980's the most common way people could interact with their devices was through command line interfaces, which though efficient, aren't really designed for casual users. This all changed with the introduction of the Macintosh by Apple in 1984. It was the first mainstream computer to use a GUI, standing on the shoulder of nearly two decades of innovation including work from the father of the GUI himself, Douglas Englebart, and some amazing breakthroughs at Xerox Parc.