Platonic solids are three-dimensional shapes with identical faces made up of regular polygons. There are five types: the tetrahedron (4 faces), cube (6 faces), octahedron (8 faces), dodecahedron (12 faces), and icosahedron (20 faces). Each solid has the same number of faces meeting at each vertex, making them highly symmetrical. These shapes are named after the ancient Greek philosopher Plato, who associated them with the classical elements: earth, air, fire, water, and the cosmos. Platonic solids have been studied in mathematics, art, and science, and they play a significant role in fields like crystallography and geometry.