A tetrahedron is a three-dimensional geometric shape that has four triangular faces, six edges, and four vertices. It is one of the simplest forms of a polyhedron and is classified as a type of pyramid. The most common tetrahedron is the regular tetrahedron, where all four faces are equilateral triangles, and all edges are of equal length. Tetrahedrons can be found in various fields, including chemistry, where they represent the molecular structure of certain compounds, such as methane. They are also used in architecture and design due to their strength and stability. The shape is significant in mathematics and is often studied in geometry.