Asking 2 question

[defaultkey]

1. what is the different of 96 and 104 ?
2. why do you make the string *example unsigned char SumB[16], LastABlock[16], MacAESTag[16], Key[16], Double[16]; but the size is 0x0 ( it mean that input of 1 string Key[i] = 4 bit, then 4 x 16 = 64, actually the size of AES-128 key input is 128) ? thank you..