count(): It returns the number of rows in a table satisfying the condition specified in the WHERE clause. It would return 0 if there were no matching conditions.

SELECT COUNT(*) FROM category WHERE ‘status’ = 1;
distinct(): It is used to return only different values. In a table, a column often contains many duplicate values, and sometimes we want to list the different values. It can be used with aggregates functions.

SELECT DISTINCT class FROM College ORDER BY department