Final answer:
A left outer join returns all rows from the left table with matching rows from the right table; while a right outer join does the opposite. The choice between them depends on which table's records are of primary interest. Neither join is more correct than the other; it is purely contextual.
Step-by-step explanation:
The difference between a left outer join and a right outer join in SQL is the direction from which the records are retained when there are no matching rows in the joined table. A left outer join returns all the rows from the left table and the matching rows from the right table, meaning if there are rows in the left table that do not find a match in the right table, these rows will still appear in the result set with null values for the columns from the right table.
In contrast, the right outer join will return all the rows from the right table and the matching rows from the left table. In terms of grouping data, using a left join might make more sense if the table on the left is the one you want to prioritize, such as when it contains the main set of records you need to display or analyze. Conversely, a right join might be used when the right table is of primary interest.
Switching between a left and right join does not reflect one table being more correct than the other; it all depends on the context and what records you want to ensure are included in your result set. Hence, neither join is inherently superior or 'more correct' than the other; it's about choosing the right tool for the task at hand.