What is the purpose of expository text

if this is a true or false question its true

i go to the store and buy some cheese,suddenly there was akward silence.   out of no where comes a ninja, and he takes an apple, and chokes the cashier, until he passes out.   the disapeared in a puff of smoke.   the cashier went to the doctor, and everything was fine again.   they all lived happily ever after without anymore ninjas.

the end

go to buy cheese= exposition

akaward silence= rising action

ninja chokes the cashier= climax

cashier goes to the doctor= falling action

they live happily ever after= resolution