Knowledge graphs connect concepts across dimensions, unlike simple taxonomies.
A knowledge graph is a collection of facts interconnected in a network, storing information as concepts rather than just labels or numbers. It works like a smarter database that imitates human memory. A taxonomy is much simpler, focusing on one characteristic like what kind of thing something is. Elephants are mammals in a taxonomy. But you cannot relate entities of different types. A knowledge graph lets you express that leopards eat gazelles or elephants eat bamboo, connecting different taxonomies together. It is essentially a multi-dimensional, supercharged taxonomy approach.
— The synergy between LLMs and knowledge graphs · The Edge