A "relation" in this context roughly means a table that can be manipulated with relational operations (e.g. join). https://en.m.wikipedia.org/wiki/Relation_(da

A "relation" in this context roughly means a table that can be manipulated with relational operations (e.g. join). https://en.m.wikipedia.org/wiki/Relation_(database) https://en.m.wikipedia.org/wiki/Relation_(database) EDIT: the sibling comment is right. The article's author seems confused.