This is a demonstration of the structure of Google Plus+Codes or Open Location Codes. Show me how this website works!
Open Location Code are short codes that can be used like street addresses. Instead of a pair of coordinates they encode an area. A code consists of 8 "digits", a "+" symbol and optional digits after the "+". Every two digits specify the area more accurately. The digits are represented in base 20 with a character set that avoids similar looking characters.
You can find more information on plus codes on Google's website plus.codes or on Wikipedia Open Location Code. For technical information there is a Github repository open-location-code