a combination of all rows in one table with all rows in another

a relational operation that will merge all the values from one table with all the values from another table

The Cartesian product of a set of tables is the table consisting of all possible rows such that is the concatenation of a row from the first table, a row from the second table ...and a row in the th table.

(RA) The result of the join of two relations with no join attributes specified, as defined in set theory. See also cross join. join.php

A join with no join condition results in a Cartesian product, or a cross product. A Cartesian product is the set of all possible combinations of rows drawn one from each table. In other words, for a join of two tables, each row in one table is matched in turn with every row in the other. A Cartesian product for more than two tables is the result of pairing each row of one table with every row of the Cartesian product of the remaining tables. All other kinds of joins are subsets of Cartesian products effectively created by deriving the Cartesian product and then excluding rows that fail the join condition.

A Cartesian join will get you a Cartesian product. A Cartesian join is when you join every row of one table to every row of another table. You can also get one by joining every row of a table to every row of itself.

In mathematics, the Cartesian product is a direct product of sets.