Cement is a binder that is used in construction to set, harden, and bind other materials together when mixed with water. The most common type is ordinary Portland cement, which is suitable for general concrete construction. Other types include Portland pozzolana cement and white cement. Cement is graded based on its compressive strength and setting time. Laboratory tests are conducted to determine properties like fineness, setting time, strength, heat released during curing. Field tests include checking for smoothness, sinking rate in water, and ability to set without cracking.