What term describes aircraft classifications for providing runway separation?

The term that describes aircraft classifications for providing runway separation is "categories." In air traffic control, aircraft are grouped into categories based on their characteristics, such as weight and wingspan, which are crucial for ensuring safe separation between aircraft during takeoff and landing operations. This classification helps controllers apply specific separation standards and procedures, enhancing safety and efficiency in managing runways.

Categories are typically defined by the International Civil Aviation Organization (ICAO) and used in both planning and operational scenarios. Other terms like types, designators, and models may refer to different classifications or specifications but do not accurately capture the specific grouping related to runway separation requirements as effectively as "categories."