Do SQL joins change the original tables?

 No, SQL joins do not change the original tables. A SQL join is simply a way to combine rows from two or more tables based on a related column. It creates a temporary result set that combines data from the joined tables, but it does not modify or alter the tables themselves.

For example, when you perform a JOIN (such as INNER JOIN, LEFT JOIN, etc.), the result is just a new table-like output, typically displayed in a query result. The original tables remain unchanged in the database.

If you want to make permanent changes to the tables, you would use SQL commands like INSERT, UPDATE, or DELETE, which explicitly modify the data in the tables.