AES was designed as a challenge to the public to propose candidates. NIST -- The National Institute for Science and Technology, announced the competition in 1997, and in 2001 declared a winner: a cipher designed by Dr. Joan Daemen and Dr. Vincent Rijmen.
AES shows its DES ancestry: it is a block cipher, where the plaintext undergoes several rounds of "bit mixing" comprised of substitutions, transposition, and Bitwise XOR with key bits. AES is fast, versatile, and apparently robust, its can be implemented with a choice of three key lengths, each of sufficient size for today's computers. AES very quickly unseats DES almost everywhere.