Ideas are
a. the way words and phrases are used to tell the story
b. the descriptive words and phrases make the writing interesting
c. the key elements of the story and the details that support them
d. the way sentences are written and flow together to tell the story

Ideas are the key elements of the story and the details that support them. Idea is among the six traits that are very necessary to follow for effective writing. The ideas of the story contains the main message  and the concept of the story. It is also made up of all the other supporting details that develop the theme of the story. A good writer prefers details that are very interesting and informative and not the obvious ones. The writer must repeat what the reader already knows. It is always an edge to be able to convey an idea in the most unique and extraordinary way.