Joins are more easily explained with an example:

To simulate persons and emails stored in separate tables,

Table A and Table B are joined by Table_A.id = Table_B.name_id

Only matched ids' rows are shown.

Common Outer Join Are Left and Right Join

Matched ids and not matched rows for Table A are shown.

Matched ids and not matched rows for Table B are shown.

Note: Outer join is not available on MySQL

Joins are more easily explained with an example:

To simulate persons and emails stored in separate tables,

Table A and Table B are joined by Table_A.id = Table_B.name_id

Inner Join

Only matched ids' rows are shown.

Outer Joins

Matched ids and not matched rows for Table A are shown.

Matched ids and not matched rows for Table B are shown.

Matched ids and not matched rows from both Tables are shown.

Note: Full outer join is not available on MySQL