Pitch
The story in one to three sentences that spark desire: protagonist, want, obstacle, stakes.
The pitch condenses the story into one to three sentences whose mission is to spark desire — in an editor, a reader, a jury. Its minimal grammar holds four elements: a characterized protagonist, a want, an obstacle, stakes. "When X happens, Y must do Z, or else W" is the most common template.
Beyond the commercial exercise, the pitch is an instrument of lucidity: a story you can't pitch usually has a foundation problem — no clear want, no real obstacle, no stakes. Writing it early (and revising it often) provides a compass during drafting: every scene should be able to justify its place against the pitch.
Example
"An art restorer finds a murder confession beneath the varnish of a family painting — her own family's."