Plein air painting is an artistic practice where artists create their works outdoors, capturing the natural light and atmosphere of a scene. This technique allows painters to observe and depict the changing conditions of the environment, such as light, color, and weather, in real-time. The term comes from the French phrase meaning "in the open air." Impressionist artists, like Claude Monet and Pierre-Auguste Renoir, popularized this style in the late 19th century, emphasizing spontaneity and the beauty of nature. Today, plein air painting remains a popular method for artists seeking to connect with their surroundings.