Geometric shapes are precise edged and mathematically consistent curves, they are pure forms and so consist of circles, squares, spirals, triangles, while geometric forms are simple volumes, such as cubes, cylinders and pyramids. They generally dominate architecture, technology, industry and crystalline structures.

In contrast, organic shapes are free-form, unpredictable and flowing in appearance. These shapes, as well as organic forms, visually suggest the natural world of animals, plants, sky, sea, etc. The addition of organic shapes to a composition dominated by geometric structures can add unpredictable energy.

Credit: Wikipedia