The translational symmetry of the Bravais lattices (the lattice centerings) are classified as follows:
• Primitive (P): lattice points on the cell corners only.
• Body (I): one additional lattice point at the center of the cell.
• Face (F): one additional lattice point at the center of each of the faces of the cell.
• Base (A, B or C): one additional lattice point at the center of each of one pair of the cell faces.
When the fourteen Bravais lattices are combined with the 32 crystallographic point groups, we obtain the 230 space groups. These space groups describe all the combinations of symmetry operations that can exist in unit cells in three dimensions. For two-dimensional lattices there are only 17 possible plane groups, which are also known as wallpaper groups.