From RFC 5246, section 6.2.3.3: AEAD Ciphers:
AEAD ciphers take as input a single key, a nonce, a plaintext, and "additional data" to be included in the authentication check, as described in Section 2.1 of [AEAD]. The key is either the client_write_key or the server_write_key. No MAC key is used.
I am not able to understand what it means? what difference it has compare to CBC?