ECB vs CBC Encryption

Well, EBC, or electronic codeblock, is a block cipher that operates

block cipher _mode_

Because I chose AES in 256-bit mode

with 256-bit _key_

AES is operating on 256-bit blocks at a time

It operates on 128-bit blocks.

etc, etc.

Wikipedia page on modes of operation is a better and more correct introduction: https://en.wikipedia.org/wiki/Block_cipher_modes_of_operatio...