What is the relationship between the Plot and the conflict?

Plot is a more general term than conflict. The plot defines the full course of a story told in a novel, short story, play, film, etc. The conflict is a specific point which the plot may center upon. Plot is generally made up of conflicts and their resolutions.

There may be several conflicts throughout the course of the plot. The conflicts may be come in many different styles and in varying degrees. So that a simple conflict may involve a character and an inanimate object that inactively works against the character, eg. a character's car breaks down at particularly inopportune moment. Or a more complex conflict could involve several levels of deception against a character, eg. a trusted companion reveals themselves to have been the villain all along.

Conflict usually falls into one of four types: character vs. character, character vs. society, character vs. self, or character vs. nature.