I'm going to sound like a total newb... but what exactly does a GUI do? I looked it up on wikipedia and it tells me:
In computer science, a graphical user interface or GUI, pronounced /ˈɡuːi/ ("gooey")[1] is a type of interface that allows users to interact with electronic devices through graphical icons and visual indicators such as secondary notation, as opposed to text-based interfaces, typed command labels or text navigation. GUIs were introduced in reaction to the perceived steep learning curve of command-line interfaces (CLIs),[2][3][4] which require commands to be typed on the keyboard.
So if it is just using icons, what purpose does this have with monero; or any other crypto currency for that matter? It seems like a really important factor to a coins success... and even though I've always looked over it for a short while when reading posts, now I would like to fully understand what it is, what it does, and why is it important for monero to have one.