Modern architecture refers to a style of building design that emerged in the late 19th and early 20th centuries. It emphasizes simplicity, functionality, and the use of new materials like steel and glass. This approach often features open spaces, clean lines, and a lack of ornamentation, focusing on the idea that form should follow function. Key figures in modern architecture include Le Corbusier and Ludwig Mies van der Rohe, who championed these principles. Modern architecture also paved the way for various movements, such as Brutalism and International Style, which further explored innovative designs and urban planning concepts.