In standards terms, asphalt emulsion is a dispersion of asphalt binder droplets in water stabilized by an emulsifying agent, classified by ionic charge and setting behavior. Standards define grades by measurable properties such as viscosity, sieve residue, storage stability, demulsibility or breaking behavior, and residue characteristics after evaporation. The definition is practical and test-linked: it exists to support procurement, acceptance testing, and predictable field performance. For industrial buyers, the key is to specify the grade designation and referenced test methods, not just “asphalt emulsion” as a generic description.