Updated 4/19/23
A taxonomy, in the badge context, is a representation of an entire badge system and how one badge relates to another. It is beneficial for earners to see the options when they look at what you have to offer. Sometimes, the taxonomy represents a framework developed to structure a badge program.
In the early days of badging, taxonomies were sometimes called "constellations." Think of a constellation of stars; you can see the individual stars, but if you take a step back, you might also visualize the Big Dipper. That is a taxonomy at work.
As you think about building out a taxonomy, remember that template attributes, public collections, and recommendations can help represent your badge program.