What are the differences between SQL Override and Update Override? - ETL

What is Update Override? What are the differences between SQL Override and Update Override?

Update Override:

- An option of TARGET instance
- The Target table is updated based on Primary Key values.
- To update the target table on non-primary key, default query need to be generated.
- The Query should override as per the requirement by including a condition in where clause of the default query

SQL Override:

- An option available in Source Qualifier and Lookup Transformation
- Joins, Filters and Group By and Order By clauses are included to override