I cannot see a single question mark, so that does not qualify as a question. After reading it four times I am starting to have some idea what you meant, but still it is a bit too mixed up together. Could you rephrase that so that we know what exactly you are asking?
Basic thing is that 8 bit cpu can do operations on 8bit chunks of data. Like adding two 8bit numbers or doing an OR on two 8bit numbers.
On the other hand most 8bit micorocontrollers will have much more than just 256 bytes of memory (that 8 bits allow) so the address could be for example 16bit, but you would need two operations to say increment that adress, since the cpu can only process 8 bits at a time.