Her pithy explanation left us with no confusion over how she felt about the issue. (to the point, brief but meaningful)

He was a man of few words but his succinct remarks gave us clear answers to our questions.

These three and the word laconic , in my opinion are interchangeable. They all mean the same thing and any one can be used in any of those sentences. They are each others definition.

Brevity however has more to do with state of being- as in the phrase the brevity of live- the shortness of the time of life- when one is terse, they are speaking with brevity- it is the quality of or state of being terse; brief; succinct, laconic . . .

succinct means ‘to the point’ like as in a description. you don’t rattle on in flowery detail you just tell the description.

pithy means (from thefreedictionary.com) precisely meaningful; forceful and brief, as in ‘a pithy comment’

laconic is using few words. being concise.

brevity is ‘short’ like not lasting very long. hope some of this helped.

Pithy – brief, yet forceful and to the point, often with an element of wit.

Succinct – expressed with brevity and clarity, with no wasted words.

Laconic – using very few words.

Brevity – use of few words.

all they words pretty much almost have the same definition. Hope this helps.