The append operation is based on the names of the column headers in both tables, and not their relative column position. The final table has all matching columns from all tables appended. If the tables don’t have matching columns, null values are added to the unmatched column. The tables will be appended in the order in which they're selected, starting with the Primary table.
You can perform two types of append operations.With an inline append, you append data to your existing query until you reach a final result. The result is a new step at the end of the current query. With an intermediate append, you create a new query for each append operation.
Security Note: Privacy Levels prevent a user from inadvertently combining data from multiple data sources, which may be private or organizational. Depending on the query, a user could inadvertently send data from the private data source to another data source that might be malicious. Power Query analyzes each data source and classifies it into the defined level of privacy: Public, Organizational, and Private. For more information, see Set privacy levels (Power Query).
