THAT'S NOT FUNNY or I DON'T GET IT.        

Determined at once by what is and has been said. what is and had been heard, what is and has been understood as well as the general levels of inebriation as experienced, drunk or quaffed by the listening audience, the joke or jest if you like, presented orally in comedy clubs with the usually overdone physicalisations of the comedienne, more than usually receives laughter of the audience in response. People as in audiences,  captive or otherwise, most often get the laugh, the humour, the point of the joke as they, the many of the audience are also aware of the understandings and situations that led to the initial creation of the jest itself. 

Buoyed as they are on the four major reasonings or drives if you like of human communication, those being necessity, the recognition of others apart from self, the presenting of oneself to others and complaint/opinion, jokes in general work because they, in their telling, create often an alternate consideration by way of word placement and choice within the joke of what the audience already knows and mutually understands.

Not withstanding, the joke garners the best use (as it is assumed today) of human communication; 

a joke provides  a dearth of actual spoken words and therefore a crispness of what is to be communicated, a joke if told well to a fitting audience supplants the need for personal or higher logics,                               a joke provides with it's punchline,  both a functional and easily believable outcome/ending for it's story,            a joke  gives most of it's listeners a chance to laugh at the misfortunes and malapropisms of one's real life.                                                                                        

Indeed and also as born from the selfsame parameters of delivered speech in communication, the conversation, daily and general conversation  (at once an art form in itself) continues still, via  it's particularisations of words and their meanings, the timings of such arrangements and the capacity for these word orchestrations  to draw the same new, mutual and inclusive understanding from the many of the participants of conversation.