SQL Server: What is the difference between CROSS JOIN and FULL OUTER JOIN?

Question

What is the difference between CROSS JOIN and FULL OUTER JOIN in SQL Server?

Are they the same, or not? Please explain. When would one use either of these?

Answer 1

One thing that might not always be obvious to some is that a cross join with an empty table (or result set) results in empty table (M x N; hence M x 0 = 0)

A full outer join will always have rows unless both M and N are 0.