My car,like many recent models,has a feature which allows me to display on my screen the *exact* location of my vehicle...meaning GPS coordinate (e.g., +042 00 10,-072 23 55) and also the city and state/province. Two weeks ago my better half wanted to go to Niagara Falls,*Canada*...so,of course,we went. Crossing the Rainbow Bridge (a very impressive experience) you see,about half way across,a US flag and Canadian flag within a few feet of each other. Half way between them is the actual border. At that exact point my display changed from "NY" to "ON".
I don't know about you but that *astounds* me!
“I had an idea that the technology involved with CDs (lasers) was complex”
Also it does some amount of on-the-fly error correction.
GPS has also been a game changer, as are the detailed maps generated from satellite data.