When using the join tool, what must match for the join to be successful?

The join tool in Alteryx requires that the field types match for a successful join operation. This is crucial because the join process combines data based on specific fields from two or more data streams. If the field types are different, even if the names and values are similar, the system will not be able to perform the join correctly. For instance, if one field is of type integer and the other is a string, they cannot be joined because Alteryx cannot compare these incompatible data types directly. Ensuring field types are the same allows for accurate and meaningful data merging, thereby enhancing the overall integrity of the output data.