The Rijndael algorithm, chosen as the Advanced Encryption Standard (AES) to replace DES, can be categorized as an iterated block cipher with a variable block length and key length that can be independently chosen as 128, 192 or 256 bits. Below you have a summary of the differences between AES and Rijndael. AES is the advanced encryption standard defined by FIPS 197. It is implemented differently than Rijndael:
FIPS-197 specifies that the block size must always be 128 bits in AES, and that the key size may be either 128, 192, or 256 bits. Therefore AES-128, AES-192, and AES-256 are actually: Key Size (bits) Number of rounds Block Size (bits) AES-128
128 10 Rounds
128 AES-192
192 12 Rounds
128 AES-256
256 14 Rounds
128
Some book will say “up to 9 rounds will be done with a 128 bits keys”. Really it is 10 rounds because you must include round zero which is the first round.
By contrast, the Rijndael specification per se is specified with block and key sizes that may be any multiple of 32 bits, both with a minimum of 128 and a maximum of 256 bits.
Reference(s) used for this question:
KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 4: Cryptography (page 153).
and FIPS 197 and https://en.wikipedia.org/wiki/Advanced_Encryption_Standard