What type of join returns only records where there is a match between entities?

The INNER JOIN is the correct answer because it retrieves only the records that have matching values in both tables involved in the join. When using this type of join, the result set consists solely of rows from each table that share a common key or criteria. This is essential when you want to focus only on those items that are directly related and ignore any that do not have corresponding matches in either table.

In contrast, the other join types do not solely focus on matching records. For instance, a FULL OUTER JOIN returns all records from both tables, regardless of whether there is a match, filling in with NULLs when there is no corresponding record. A LEFT JOIN retrieves all records from the left table and the matched records from the right table, inserting NULLs for unmatched records from the right. Similarly, a RIGHT JOIN retrieves all records from the right table and the matched records from the left table, with NULLs for unmatched records from the left. These behaviors make INNER JOIN unique in its exclusivity to matched records only.