Cementitious materials is an academic concept and research area investigating the composition, hydration reactions, microstructure formation, and resulting engineering properties and long-term performance of materials that exhibit binding capabilities upon chemical reaction, typically with water. This field examines the fundamental chemistry and physics governing the transition from a powder or suspension to a solid matrix, the factors influencing strength, durability, and volume stability, and explores novel formulations and sustainable alternatives. Its significance stems from the critical role these binders play in concrete and other construction composites essential for global infrastructure and development.