What are the differences between "Event Attribute" and "Event Attribute (Perspective)?

Hi everyone,
When I upload the event log file, I see that Apromore detects the type of attribute (Case ID, Activity, etc.) automatically. But I do not quite understand that what are the differences between “Event Attribute” and "Event Attribute (Perspective)?
Can you help me explain it?
Thank you in advance.

If during log import you tag a column (for example the Role column) as an Event Attribute, then this attribute will be available in the Filters and in the Dashboard. But, you will not be able to use it as a Perspective in the Process Discoverer, i.e. it will not appear here:

If you tag the Role column as an “Event Attribute (perspective)”, then the Role attribute will appear as a perspective as shown in the screenshot above.

Thank you for your explaination.