The difference between NATURAL JOIN and CROSS JOIN in SQL is quite straightforward. A NATURAL JOIN joins two tables implicitly, based on the common columns in the two tables that are joined. Common columns are the columns that have the same name and datatype. A NATURAL JOIN can be an INNER JOIN, a LEFT OUTER JOIN, or a RIGHT OUTER JOIN. Meanwhile, CROSS JOIN produces a result set that contains all the attributes of both tables, including duplicate and common columns.