Texel

A texture is a grid of these samples, and drawing a surface comes down to deciding which one (or ones) fall under each screen pixel. The relationship is rarely one-to-one: a wall seen edge-on crams many into a single pixel — the case mipmaps exist for — while a wall up close stretches one across many pixels, the case for filtering. The word is a portmanteau of texture element, coined by analogy with pixel (picture element) and voxel. Hardware samplers fetch texels through the texture cache, and throughput — how many a GPU can read and filter per second — is a classic bottleneck, which is why block compression exists to shrink them.