What is the function of the SQL ROWNUM function?

In SQL, the ROWNUM function is commonly used to return row numbers in a query result set. The ROWNUM function can be utilized to sort the result set in a specific order and select a certain number of rows from the result set. This function is often used in conjunction with a SELECT statement, where it can be used in the WHERE clause to limit the number of rows in the result set, or in the ORDER BY clause to sort the result set in a specific order. The ROWNUM function is implemented in many database management systems, such as Oracle.