Texel Density
How much texture resolution a surface gets per unit of area.
Texel density measures texture pixels per meter of surface. Keeping it uniform across assets means no object looks blurrier or sharper than its neighbors when placed in the same scene, which is why asset libraries built for games (including this one) hold texel density consistent.
Related: Mesh
These fundamentals are covered hands-on in Blender Geometry Essentials 01, free with a free account.