A very concise article, written in plain English that describes the GPS Network, it’s origins and uses. The Wikipedia article, on the other hand, is much better suited to Information Sponges or Geeks Only
Thanks to an invisible armada of incessantly broadcasting satellites, collectively called the Global Positioning System, and to the explosive proliferation of GPS receivers in gadgets from dashboard map units to cell phones to dog collars, even the cartographically clueless are now good to go.
So if you are “Cartographically Clueless” (I Love that phrase), please read the Washington Post Article, and get a clue! Did you know that GPS is all about keeping time, actually incredibly accurate time using Atomic Clocks in space?. If you MUST know how and not satisfied with just using GPS, read the Wikipedia posting. Take good notes, there will be a quiz!