We like movies because we like to worry. The story can be comedic or dramatic, but the principle is the same.
Dramatic action is when a character wants something and takes action to get it. Conflict is when an obstacle or antagonist gets in the way. The clearer and more focused the obstacle or antagonist, the more acute the conflict will be.
Drama is conflict in the present. Tension is conflict in the future.
The episode on sound, which I've embedded below, should be required viewing for all filmmakers. What I liked was how the Sound Designer preferred being involved in casting to help choose actors based on how they sound together. This is a nuance of filmmaking overlooked almost all the time and thus raises the caliber of filmmaking to a whole new level.
You can find the rest of the episode links on Elver's post.