Impressionism began in the 19th century as artists painted outdoors to capture fleeting effects of light and color, influenced by photography, and Expressionism originated in Germany as a reaction to styles like naturalism that sought to distort reality and convey emotional experience rather than physical forms through vivid colors and compositions. Major Impressionist artists included Monet, Renoir, Degas, Cassatt, Pissarro and Sisley and Expressionist works aimed to provoke strong emotional responses.