A value proposition is a clear, one-to-two-sentence statement of what a product does, for whom, and why it's distinctly better than the alternatives. It identifies the target customer and the competitive positioning, used to anchor brand positioning, marketing messaging, sales scripts, landing pages, and product roadmap decisions around a single promise. It is the answer to the question "why should this specific customer choose this product over their other options," written tight enough that the buyer can repeat it after hearing it once.
The most-cited template, from Geoff Moore's Crossing the Chasm (1991), runs: "For [target customer] who [needs / wants X], [our product] is a [product category] that [key benefit]. Unlike...