Concisely
in a few words, in a word, succinctly, concisely, in brief, in short, in sum, in a nutshell, in capsule form, in outline, shortly, curtly, abruptly, brusquely, laconically, tersely, summarily, to be brief, to put it briefly, to cut the matter short, to sum things up, to sum up, to come to the point, to come straight to the point, to make a long story short*.
Antonyms at length, verbosely, long-windedly.