Brownstones are a type of residential building commonly found in urban areas, particularly in cities like New York City. They are typically made of brown sandstone, which gives them their distinctive color and appearance. These buildings often feature three to four stories, large windows, and decorative elements like stoops and cornices. Originally built in the 19th century, brownstones were designed to accommodate middle-class families. Today, they are highly sought after for their historic charm and architectural beauty. Many have been renovated into modern homes while preserving their classic features, making them popular among homeowners and real estate investors alike.