Wireframe
A wireframe is a deliberately plain layout diagram used to agree structure and priority before visual design begins.
In full
A wireframe is a low-fidelity representation of a page showing what content appears, in what order, and at what relative prominence, using placeholder blocks rather than finished visual design. Stripping out colour, imagery, and typography is the point: it forces conversation about hierarchy and content rather than aesthetics. Wireframes are cheap to change, which makes them the right place to resolve structural disagreements. Their limitation is real, though: a wireframe cannot tell you whether something will feel considered or expensive, which is why high-fidelity design should follow reasonably quickly.
Why it matters
Structural mistakes caught at wireframe stage cost minutes. The same mistakes caught after build cost a redesign.