byte和octet的区别

The term byte has traditionally been the most popular in common parlance for a set of eight bits, especially in North America. However, it is technically not the correct term.
A byte is, formally, the smallest unit of data that can be read from or written to at one time in a computer system. In almost all cases today, that is indeed eight bits, but there are have been some systems where a byte was not eight bits. Some older 36-bit computers used 9-bit bytes, and there were also systems that had byte sizes of 6 or 7 bits, or even variable-sized bytes.
For this reason, many people, especially techie professionals, prefer the term octet, which clearly and unambiguously implies “eight”. This term is much more common outside North America.

通常意义上我们会约定一个 byte 为 8 bit，但是一个 byte 并非绝对等于8 bit，有些36位系统一个 byte 为 9 bit，甚至有些系统一个 byte 是 6 bit 或者7 bit。
所以处于这些原因，一些技术专家会用 octet ，表示绝对的 8 bit 的字节。