Query Motivation for Cross Joins
A CROSS JOIN gives you the Cartesian product of all the rows in the two tables and then applies any filtering from the WHERE clause. It rarely serves a purpose for your more common table relationships, but there are some occasions where it's handy.

For example, you may need to assign relationships between a static table of Properties and some Items stored in another table. The easiest way to add a new Item and relate it's needed Properties would be to insert the results of a CROSS JOIN between the two tables into a linking table between them. Specific values for those properties could then be added later via other interfaces, but they would have the framework assigned already without having to hard-code the interface.