The original usage of the term "byte" was to refer to fields of variable length consecutive bits on a bit-addressable machine: https://en.wikipedia.org/wiki/Byte#History
Nowadays a byte is conventionally eight bits, especially for measures like "megabyte", but the term octet is often used to avoid ambiguity. Commonly they're used for pointers, yet often only words are addressable by machine instructions (e.g. many ARM instructions take a byte address yet raise a hardware exception on use of unaligned addresses).
Nowadays a byte is conventionally eight bits, especially for measures like "megabyte", but the term octet is often used to avoid ambiguity. Commonly they're used for pointers, yet often only words are addressable by machine instructions (e.g. many ARM instructions take a byte address yet raise a hardware exception on use of unaligned addresses).