Aladdin tries tries in vain to win her hand with wealth, then rescues her from marrying the villain, with the aid of a genie. But he wins her only through being himself. By comparing a story to the concept, you can easily see where a story moves off in some other direction. For example, if Aladdin spent most of the story roaming the countryside with the genie, rescuing people, you would be talking about a series of stories, not a storyline. You can see that isn't really what the story is about and that section would need to come out.
High concept is a very simple concept that others can easily relate to.
High concept is when something is involved for which there is a universal pattern with which we all can easily identify. Good versus evil. High concept movies sell very well, so if you can apply the term high concept to your story, you can expect a better response. Developing a concept I suspect the reason most of us don't do much with concepts is that we never learned how to develop one. A concept is similar to a business mission statement.