Minimum words, maximum information.

Laconism is a figure of speech in which someone uses very few words to express an idea. This may be used for efficiency (like in military jargon), or for philosophical reasons (especially among thinkers who believe in minimalism, such as stoics), for better disarming a long, pompous speech (the most famous example being at the Battle of Thermopylae).

It might also simply be a consequence of poor literary education. Arguably, this is the real reason why the Spartans were concise at Thermopylae, and the rhetorical impact of their laconism was just an accident. However, Socrates held a different opinion. Plato quotes him as saying: “…they conceal their wisdom, and pretend to be blockheads, so that they may seem to be superior only because of their prowess in battle…This is how you may know that I am speaking the truth and that the Spartans are the best educated in philosophy and speaking: if you talk to any ordinary Spartan, he seems to be stupid, but eventually, like some expert marksman, he shoots in some brief remark that proves you to be only a child.” [1]

Laconism comes from Laconia (a.k.a. Lacedaemon [greek Λακεδαίμων]), the region surrounding the city of Sparta stricto censu, region which was under the control of the city.  – Wikipedia