Synonyms are words that have essentially the same meaning, and they provide some variety in your word choices, helping the reader to stay focused on the idea being discussed.
http://home.ku.edu.tr/~doregan/Writing/Cohesion.html
Please explain the use of "being discussed vs "the idea is discussed ".
"the idea being discussed" is a noun phrase, a shortening of "the idea that is being discussed". "the idea is discussed" cannot be a noun phrase and so does not fit in that sentence.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
"the idea being discussed" is a noun phrase, a shortening of "the idea that is being discussed". "the idea is discussed" cannot be a noun phrase and so does not fit in that sentence.
Synonyms are words that have essentially the same meaning, and they provide some variety in your word choices, helping the reader to stay focused on the idea [(that is) being discussed].A reduced relative clause is within the brackets. The relative pronoun and helping verb can be omitted.
Here is a web page with lots of examples: