Standard Concrete Cinder Block - Durable Building Material for Walls & Foundations #1663244 (License: Personal Use)

This is a standard 8-inch concrete masonry unit (CMU), commonly called a cinder block, made from Portland cement, aggregate, and water. Its two rectangular voids reduce material use and weight while allowing for reinforcement with rebar and grout. The rough-textured surface aids mortar adhesion during laying.

Used on construction websites, building supply catalogs, and DIY guides to illustrate basic masonry materials; matches user intent for learning about block types, purchasing, or planning home projects.