Every introductory CompSci resource I can find goes through how 8 bits are in a byte, etc. So a byte can store some 2^8 values in binary. Then when asking about four bytes, we can assume this is (2^8)^4=2^32.
But I can't find anywhere if this pattern holds up until the total amount of hard drive or memory storage. For instance, if even a single megabyte can really hold (2^8)^1000000 bits, isn't this a number so large that it could store all data in existence everywhere in the universe many times over? The number of possible combinations from a number that large would surely never be reached. Yet in reality, we all know a megabyte isn't much.
I can't help but feel somewhere that the exponentiation must stop, and we instead multiply bytes together. Or is it really the case the numbers can get this big? Such as a gigabyte representing ((2^8)^1000)^3 bits?
If I can represent a number, let's say, 1 million in 32 bits, and I wanted to store 10^50 numbers this large, wouldn't the required bits be 2^32*10^50? First of all, I'd never need to store 10^50 of any unit of data on my hard drive, that's astronomically massive, and secondly, 2^32*10^50 is quite a small number, far below (2^8)^1000000. So what's really happening here that we need so much storage, and a megabyte isn't much?