# Bits vs. Bytes * A **bit** stores a $1$ or $0$. It is the smallest building block of storage. * One **byte** is a collection of $8$ *bits*. For example, `10100011` * One *byte* can store one character  The number of possible patterns that $n$ bits can store is simply equal to: $\text{Number of patterns stored in n bits} = 2^n$ So for example: $\text{8 bits} = \text{1 byte} = 2^8 = 256 \text{ patterns}$ ### 32-bit vs 64-bit Operating Systems * In computing there are two different types of processor, 32-bit and 64-bit * A 32-bit system can access $2^{32}$ memory addresses. [Each address points to 1 byte of data](https://stackoverflow.com/a/27151523/14204006). So, a 32-bit system can access $2^{32} \text{ bytes} = 4,294,967,296 \text{ bytes} \approx 4 \text{ Gb}$ . * A 64-bit system can access $2^{64}$ memory addresses. --- References: * https://web.stanford.edu/class/cs101/bits-bytes.html * https://stackoverflow.com/questions/2724449/difference-between-word-addressable-and-byte-addressable * https://stackoverflow.com/questions/8869563/how-much-memory-can-be-accessed-by-a-32-bit-machine