Though this subject is somewhat discussed at Difference between “jargon” and “technical terms”, what are the differences?
From Merriam-Webster online:
Jargon: The technical terminology or characteristic idiom of a special activity or group.
Terminology: The special words or phrases that are used in a particular field.
Lexicon: The words used in a language or by a person or group of people. (Also: The vocabulary of a language, an individual speaker or group of speakers, or a subject.)
Can you please give examples where it is appropriate to use only one but not others.