Origin: Latin suffix -ary
Commentary has 2 different meanings across 1 category:
a written explanation or criticism or illustration that is added to a book or other textual material
"he wrote an extended comment on the proposal"
a series of comments or annotations; especially, a book of explanations or expositions on the whole or a part of some other work
"The professor handed out the commentary for Dante's Inferno, which included detailed notes explaining every metaphor and historical reference in the original poem."
In plain English: Commentary is when someone gives their own opinions and explanations about something that is happening.
"The sports commentator provided lively commentary during the final minutes of the game."
Usage: Use commentary to describe an ongoing spoken or written analysis of events, such as sports broadcasts or news coverage. Avoid using it for simple remarks or annotations unless referring to a specific collection of explanatory notes on another text.
The word commentary comes from the Middle French commentaire, which was borrowed from the Latin commentarium meaning "notebook." It entered English with this sense of written notes or observations attached to a text.