Simple taxonomies are useful and quite common, but as was mentioned earlier, they’re only the tip of the taxonomy iceberg.
Generally speaking, there are three types of taxonomies: flat (or simple) taxonomies, hierarchical taxonomies, and networked taxonomies.
To review, here is a flat or simple taxonomy:
A flat taxonomy has only one level of dependencies. In a flat taxonomy there are generic classes of data, each one having one level of specific occurrences.
Here is a graphic depiction of the flat taxonomy:
The second type of taxonomy is a hierarchical taxonomy. ...