| INNER JOIN | Only rows with a match in both tables | Never (unmatched rows are dropped entirely) |
| LEFT JOIN | All rows from left + matched rows from right | Right-side columns when left has no match |
| RIGHT JOIN | Matched rows from left + all rows from right | Left-side columns when right has no match |
| FULL OUTER | All rows from both tables | Either side when the other has no match |
| CROSS JOIN | Every combination (no ON condition) | Never (all combinations are output) |
| SELF JOIN | A table joined to itself via aliases | Depends on whether LEFT or INNER is used |
| Anti-Join | Rows that have NO match in the other table | Used intentionally to find unmatched rows |
