The difference between Octet and Octonary

When used as nouns, octet means a group or set of eight of something, whereas octonary means a group of eight things.

Octonary is also adjective with the meaning: of eighth rank or order.

check bellow for the other definitions of Octet and Octonary

Octet as a noun:

A group or set of eight of something.
Octet as a noun (music):

A group of eight musicians performing together.

Examples:

"An octet of waiters sang her "Happy Birthday"."
Octet as a noun (music):

A composition for such a group of musicians.
Octet as a noun (computing):

A byte of eight bits. Abbreviation: o
Octet as a noun (computing, rare):

A group of three bits, representing any of eight possible values.