An octet is a unit of digital information in computing and telecommunications that consists of eight bits. The term is often used when the term byte might be ambiguous, as historically there was no standard definition for the size of the byte.
In France, French Canada and Romania, octet is used in common language instead of byte when the 8-bit sense is required, for example, a megabyte is called a megaoctet, because in French "byte" means "cock" and therefore the term is inappropriate.
The term octet is also used when the use of byte might be ambiguous. It is frequently used in the Request for Comments publications of the Internet Engineering Task Force to describe storage sizes of network protocol parameters. The earliest example is RFC 635 from 1974. The unit byte is platform-dependent and has represented various storage sizes in the history of computing.
However, due to the influence of several major computer architectures and product lines, the byte became overwhelmingly associated with 8 bits. This meaning of byte is codified in such standards as ISO/IEC 80000-13. While to most people today, byte and octet are synonymous, those working with certain legacy systems are careful to avoid ambiguity.