Which type of SQL join includes all records from one table and related records?

The answer focuses on the concept of an outer join in SQL, which is designed to include all records from one specified table, along with the related records from another table. If there is no corresponding match in the second table, the outer join still returns the record from the first table, filling in with nulls for the missing data from the second table.

This is particularly useful in scenarios where you need to display all records from the primary table regardless of whether they have corresponding entries in the related table. It provides a comprehensive view of the data while ensuring that no records from the chosen table are omitted, thus creating a more inclusive dataset for analysis or reporting.

In contrast, other join types have different behaviors: an inner join only includes records that have matches in both tables, a cross join produces a Cartesian product of the tables, and a self join is used to combine records from the same table based on specific criteria. These options do not fulfill the requirement of including all records from one table with their related records, thus making outer join the correct and most appropriate choice for the question posed.