This website aims to encompass multiple tools to help you understand and visualize geohashes.
It is a geocode system that encodes a geographic location into a short string of letters and digits. It was invented in 2008 by Gustavo Niemeyer.
It offers properties like arbitrary precision and the possibility of gradually removing characters from the end of the code to reduce its size. Geohashing guarantees that the longer a shared prefix between two geohashes is, the spatially closer they are together.
You can read more at Wikipedia