If a composite has a high modulus of elasticity or a high flexural strength, what exactly does that mean?

Modulus of elasticity refers to the amount of stress a material has for an amount of elastic strain. The higher the elastic modulus, the more resistant is the composite material to deformation within the elastic range. Flexural strength is more important in long-span restorations, as it refers to the strength of the composite when flexed between two points.