What are the categories of event described in the ITIL service operation book?

"Scheduled" and "normal" are not ITIL event categories - ITIL uses informational, warning, and exception to classify events by their significance and required response.

Scheduled, unscheduled, and emergency are the three categories of ITIL change types, not the event categories defined in the Service Operation book.

ITIL Service Operation classifies events into three types: informational events require no action and simply record normal operation; warning events signal an unusual situation approaching a threshold that may need attention; and exception events indicate abnormal behavior that requires immediate action. This three-tier model helps operations staff prioritize and respond appropriately to different conditions across the IT environment.

"Reactive" and "proactive" describe general approaches to IT management, not the specific event categories defined in the ITIL Service Operation framework.