Graphs in SQL
Graphs are important because they are a general way to represent many different types of data and their relationships. SQL was not meant to be a graph language (there are graph databases today), but you can model graphs in SQL.
Taxi cab geometry
The terminology in graph theory pretty much explains itself; if it does not, you can read some of the books suggested in the appendix for graph theory. Graphs are important because they are a general way to represent many ...