A story with momentum makes me want to know what’s going to happen next, and makes me care about the characters, objectives, conflicts, and action.
There is a distinction between author, narrator, and character.
The author creates the story.
The narrator tells the story.
The character lives the story.
These are three distinct entities, which exist on different planes.
I introduced this concept of scenes vs. summary in my post on the four ways to break down page-level craft. Here, in more detail, is what scene vs. summary is all about. And I’ve included some explanation on how the story writer can benefit from knowing this aspect of craft.