A "gray sky" refers to an overcast condition where clouds cover the sky, blocking sunlight. This phenomenon often occurs during rainy or stormy weather, creating a dull and muted atmosphere. The clouds can vary in thickness and color, but they typically appear as a uniform gray, indicating moisture in the air. Gray skies can influence mood and behavior, as many people associate them with gloominess or fatigue. However, they also play a crucial role in the ecosystem by providing necessary precipitation for plants and water sources. Additionally, gray skies can create unique lighting conditions, affecting photography and art.