Pattern is the regular repetition of elements like line, shape, color, or texture in an artwork. Patterns can be regular, with predictable repetition, or irregular, with unpredictable changes. Patterns are found everywhere in nature and are commonly used by artists. The document provides examples of patterns in artworks, including the repetition of figures, lines, shapes, and colors that create patterns in paintings by Barrington Watson, Claude Monet, and Piet Mondrian.