Which of these is not a type of roof?

The correct answer is indeed the option that identifies "Holiday" as not being a type of roof. Roof types are generally categorized based on their shape and design, and common roof styles include gable, hip, and butterfly roofs.

A gable roof features two sloping sides that meet at a ridge, creating a triangular shape at the ends. This design is preferred for its effectiveness in shedding water and snow and allows for more space in the attic.

A hip roof has slopes on all four sides, which can give a more stable structure and superior durability against adverse weather conditions. It provides a more aerodynamic shape, which is beneficial in areas prone to high winds.

The butterfly roof has a unique design that resembles the wings of a butterfly. It is characterized by two roof surfaces sloping downwards toward a central valley, allowing for effective rainwater collection.

In contrast, "Holiday" does not correspond to any recognized roof design in the context of construction and architecture, making it the correct response to this question.