These types are synonyms for TINYINT(1).
A value of zero is considered false.
Non-zero values are considered true:
The constants TRUE and FALSE evaluate to 1 and 0, respectively.
mysql>
mysql> SELECT TRUE, true, FALSE, false;
+------+------+-------+-------+
| TRUE | TRUE | FALSE | FALSE |
+------+------+-------+-------+
| 1 | 1 | 0 | 0 |
+------+------+-------+-------+
1 row in set (0.00 sec)
mysql>