Previous parts of Dialogue are indexed here:
All the parts through 12 are linked there.
Hitherto, we have taken great care to distinguish between Plot and Story -- because confusing the two leads to the biggest (and least fixable on rewrite) errors beginners make.
Which element you call Plot and which you call Story really doesn't matter much. Different "schools" of writing use different nomenclature. But I've never met a prolific professional writer who does not hold the stark distinction in mind, and finger it unerringly in beginner's manuscripts.
The Plot-Story dichotomy is very often the last thing new writers learn, and upon mastering it, they begin selling. It is hard to learn because real life does not have any such distinction.
I use "Plot" to refer to the "because-line" (a term I invented) -- the sequence of Events, Decisions, Actions that drive the visible scenes of a novel.
I use "Story" to refer to the effect the Events have on the Characters.
For me, a good novel is "about" the effect the events have on the Characters.
I have read many best selling "action-thrillers" in which the wildly adventurous Events mean nothing to the Characters -- net-net in the end of the novel, they are the same people they were at the beginning.
This lack of "Character Arc" was a requirement in Anthology TV Series like Star Trek, so the episodes (which were, technically, just that, episodes not stories) could be viewed in any order. That was required because of the way the distribution system worked.
The fiction distribution system has changed, drastically. So now we can have major Character Arcs in Series like Babylon 5, or the remake of Hawaii 5-O.
Dialogue is the show-don't-tell tool the writer has to convey the impact of Plot Events on the Character, and "tell the story."
What people say, how they say it, how what they say changes upon Event Impact, is Dialogue.
What the Characters DO in response to Events is PLOT.
Speaking is Doing!!!
In other words, spoken words are plot -- but they are also story.
Here's the thing.
Spoken Words are Theme-Plot-Character-Story-Worldbuilding.
The Dialogue makes the reader figure out (and thus believe) all those plot elements.
See Dialogue Part 11 for where in dialogue you can put exposition about your Worldbuilding that readers will believe.
So, deeds are plot. But not just the deeds. The criteria by which a given Character chooses what deed to do in response to which Event is Characterization which shows up in inner-dialogue (thoughts) as well as word said to other Characters.
The phone rings -- some Characters answer it; others wait for the Butler to answer.
Answering or waiting (with or without patience) is a deed, a plot element. WHY the answering is done, or not done, is worldbuilding. A Character shifting attitudes about phone answering is story.
For example, in scene 1, bad news arrives by ringing phone. In the final scene, the phone rings, and the Character hesitates, chewing her lip, before answering -- clearly thinking about bad news arriving by phone.
Characterization relies a lot on Dialogue, at the point where words and deeds intersect.
Here is an article (listicle) that lets you Depict a successful person. The opposite traits would work to convey that the Character is a Loser.
This is a list of what people do when things happen, and what the public looks for to find a person poised for "success."
talk about ideas
accept responsibility for failures
give credit where it's deserved
want others to succeed
ask how they can help others
ask for what they want
understand themselves (their motivations)
always listen without talking much
This is a list as old as the hills -- you can use it in a pre-historic setting, Middle Ages, or Space Age.
Each of these attitudes is backed by an upbringing that infuses self-image with strength -- and that can be transmitted only by a parent who had such an upbringing. Therefore, depicting Characters with these behaviors, reactions and responses to their world (study Captain Kirk's humor) telegraphs to the Reader that this Character will succeed, and depicts their upbringing in show-don't-tell. Sometimes it is not an actual "parent" that transmits the attitude, but a surrogate (Mentor, Sports Coach, Science Teacher, Boy Scout Troop Leader, step-father, local beat cop, etc.)
I assert it is as old as the Hills - because this set of traits is actually depicted and prescribed in the Bible, and other writings from the BCE epoch.
So Dialogue is where the rubber grips the road in writing.
With two or three well chosen words you show-don't-tell if your Character is an Executive and if she is Poised For Success -- and if the other Characters see and understand that, or may be blindsided by the Character's success (this works particularly well in Paranormal Romance).
Who will be the "winner" and who the "loser" at the end of the novel is clearly presented on Page 1, with a few well chosen words.