Plot is what occurs during a story. In the best of tales it is done in such a way that it’s clear to the reader when, this took place because that first took place. Allow me to clarify. I am writing a romantic type of story where I have a male character going on a first date. Throughout this date he demands that the woman pay half of everything. Movie tickets, popcorn, drink and even dinner. At the end of the date before leaving the restaurant he hints at a second date. The woman flatly turns him down. Not wanting to waste more gas, for he was the one who drove, he gets angry and tells her to take a cab home. The story ends with his date taking a cab that just happens to be driven by a guy who had a crush on her in high school. When he pulls up to her home she reaches in her purse preparing to pay him but he indicates that the ride is on him. She gives him her phone number and they soon fall in love. The end:)
See how it is clear how the female character went from being on a date with one guy to riding in the back of a cab be driven by another guy whom she quickly falls for? This took place because that first took place. While revising your story if you can not pinpoint the moment that this took place because that first took place, the section(s) then needs to be reworked so that is does.