Ideal Customer Profile
Also called ICP
A sharp description of the exact customer your product is best for: their size, role, situation, and pain. Not everyone who could buy, but the ones who buy fastest and stay longest.
Why it matters
Focus is the scarcest resource early on. A tight ICP tells you who to build for, who to sell to, and just as importantly who to say no to, which is how small teams win a beachhead before spreading out.