A lot of people call AES as an algorithm because it adopts Rijndael as a Standard. However, AES is more specific so that all implementations of AES conform to the 'standard' and are therefore inter$-$operable $-$ meaning they can talk to each other. One of the things that AES takes care is how diffusion is implemented. It is implemented as a combination of shiftrows and mixcolumns. The shiftrows is simply

permutation of data at byte level.

using many keys.

same as mixcolumns.

using substitution box.