De Stijl, which means 'The Style' in Dutch, is an influential art movement founded in the early 20th century. It is characterized by a strict use of geometric forms, primary colors, and a grid-based approach to composition. Key figures include Piet Mondrian and Theo van Doesburg, who sought to express a new aesthetic that reflected the harmony and order of the modern world. The movement not only impacted painting but also extended to architecture and design, promoting simplicity and functionality. De Stijl's principles can be seen in various fields, influencing later movements such as Bauhaus and Minimalism.