This refers to the main idea in the story or what the story is all about​

This question is incomplete. I assume that you need to find the word that fits with that description. The word you are looking for is Theme.

Explanation:

Literary themes refer to the main idea or the content of the literary work, regardless of gender. That is, the great themes, love, hate, death ... of literary works are treated equally in theater, poetry, narrative, etc.

It is a concept similar to that of the "artistic theme" in any art other than literature. Therefore, when we speak of literary themes, we refer to the matters dealt with in poems, poetry books, novels, plays, stories, etc.