The Google Knowledge Graph is a large knowledge base containing facts about people, places, books, and other kinds of entities. Some examples of Google Knowledge Graph entities include:
/m/0dl567 — Taylor Swift
/m/02_286 — New York City
/m/030q7 — FIFA World Cup
/m/045c7b — Google
/g/11j48g0yyn —The Matrix Resurrections
Every entity in the Google Knowledge Graph has a unique ID, also known as an MID which stands for "machine identifier". These IDs have the same format and all begin with either
/g/1 followed by the base-32 representation of an auto-incrementing numeric ID.