The AND keyword is used to add more conditions to the query.

Name | Age | Gender | —— | —— | —— | Sam | 18 | M | John | 21 | M | Bob | 22 | M | Mary | 23 | F |

SELECT name FROM persons WHERE gender = 'M' AND age > 20;

This will return:

Name | —— | John | Bob |

using OR keyword

SELECT name FROM persons WHERE gender = 'M' OR age < 20;

This will return:

name | —–| Sam | John | Bob |

These keywords can be combined to allow for more complex criteria combinations:

SELECT name
FROM persons
WHERE (gender = 'M' AND age < 20)
   OR (gender = 'F' AND age > 20);

This will return:

name | —–| Sam | Mary |