Displacement mapping
Actually moving the surface points outward according to a height texture, so the detail has a real silhouette and shadows itself.
Unlike normal mapping and parallax mapping, which only fake the shading or nudge texture coordinates, here the geometry is genuinely pushed along the normal. So a brick wall gets an edge that juts against the sky instead of flattening out at grazing angles. Robert Cook described the idea in 1984 in his work on shade trees and the Reyes architecture.
The cost is geometry: a flat surface has no points to move, so the technique needs a dense mesh or runs together with tessellation that spawns the points on the card. The height data lives in a grayscale texture — the same heightmap terrain uses — read in the domain shader. Offline renderers have used it since the 1980s; real time only got it practically with DX11's tessellator.