Product and interface
The framing that a customer is not buying a product but hiring it to make progress in a situation.
Also called JTBD
The useful discipline is the situation rather than the vocabulary: what was happening immediately before someone went looking, what they used instead, and what would have to be true for them to stop. It relocates competition — a project-management tool competes with a spreadsheet and a group chat, not only with other project-management tools.
It is at its most valuable in pricing and positioning, where the alternative being displaced sets the reference price far more than any competitor's list does.
“Would you use this?” produces agreement and no information. Ask about the last time the problem occurred: what they did, what it cost, what they tried first. Past behaviour is evidence; stated intent is politeness.
The definitions are the easy part. Whether the figure on your dashboard was computed this way is a different question, and usually the more expensive one.