Which parameters can be included with an event hit for reporting?

When sending an event hit to Google Analytics, the required parameters are Category and Action. Optional parameters include Label and Value. The 'Value' parameter allows you to assign a numerical value to an event, which can be useful for tracking revenue or other quantifiable metrics associated with user interactions. 'Unique Events' and 'Total Events' are metrics calculated by Google Analytics based on the event data received, not parameters sent with the event hit. 'Event' is a general term for the hit type, not a specific parameter.