Hand-drawn view of an open-air infinity pool on the rooftop

Quick answer：

An infinity pool, also known as a vanishing edge pool, is a type of pool where one edge seems to extend to the horizon. This creates an illusion of the water extending endlessly into the distance, often over the edge of a building or cliff. Rooftop infinity pools are a luxury feature often found in high-end resorts or private homes, providing a unique vantage point for relaxation and entertainment.