The snow-line, also known as the snow boundary or the snow level, refers to the point on a mountain or hill where snow and ice begin to accumulate. This threshold is influenced by various factors such as temperature, altitude, and precipitation. Other synonyms for the snow-line include the snow limit, the snow zone, and the snow bound. In addition, there are regional terms such as the timberline, the frost line, and the ice line that pertain to specific areas where the snow-line occurs. Regardless of the terminology used, the existence of the snow-line is a critical factor in shaping the landscape, ecological systems, and recreational opportunities in mountainous regions.