In combinatorics, a k-ary necklace of length n is an equivalence class (a grouping for which there exists an equivalence relation) of n-character strings over an alphabet of size k, taking all rotations as equivalent. It represents a structure with n circularly connected beads which have k available colors. Formally, one may represent a necklace as an orbit of the cyclic group acting on n-character strings, and a bracelet as an orbit of the dihedral group. One can count these orbits, and thus necklaces and bracelets, using Pólya's enumeration theorem.