Every story has conflict; whether that be grating between two people, the MC against nature, fighting ideas, battling against some inner demon, or rebellion against authority. Many conflicts will arise within the confines of a story, not just the overall challenge that takes our MC from point A to point B. Each scene should contain some situation that present(s) a conflict(s).
These scenes build tension. They inform the reader about the MC and the world around them. They move the story’s plot toward resolution. They show character(s) growth or regression as the story progresses. There may be a strong push to suppress the conflict, but that attempt will also present conflict. Some characters will fight changes the conflict represents. Others will embrace the change as their obsession.
The conflict in a single scene does not necessarily have to be related to the conflict of the overall story. For instance, a writer may be telling the story of a sailor who survived the attack on Pearl Harbor, a scene within that story might deal with said sailor having an argument with their significant other about how many children they should have. Such a scene will show the personality of characters; it will show life goals of said character and partner, it will show how they deal with stresses of everyday life. When the story hits its climax; i.e., when the bombs begin falling, and the ship begins sinking, the sailor might look back to this argument with regret and find a reason within it to fight for his survival. On the other hand, all thought of the significant other may be relegated to a deeply hidden recess of the mind to give the character room to do what’s required to get out of and off of the ship and thereby survive.
Conflict drives the plot. It is the multifaceted struggle challenging the MC and the driving force behind a story. In its many forms, conflict becomes the scaffolding for the story and the vehicle of transformation for the MC (for good or ill) into that person/creature which they become by the end of the story.