EIFS (Exterior Insulation and Finish Systems) are a non-bearing exterior wall cladding made from a layer of rigid foam insulation board covered with a reinforced surface lamina.  Traditional hard coat stucco is a non-bearing exterior wall cladding typically made from a Portland cement based material that is applied in layers over a metal reinforcement such as galvanized lath or galvanized stucco netting.

EIFS Hard Coat Stucco
EIFS can be attached using an adhesive, mechanical fasteners, or both. Hard Coat Stucco uses mechanical attachment through the metal reinforcement over most substrates. If the substrate is clean, bare masonry, the hard coat stucco can be applied directly without the use of metal reinforcement or fasteners.
EIFS can provide a minimum of R3, up to a maximum of R20 Hard Coat Stucco will provide up to a maximum of R1
Color Availability and Uniformity
EIFS is available in any color, with a high degree of uniformity and reporducibility. Hard Coat Stucco is available in limited colors, and is subject to color variability due to the varying effect of cement hydration on color development.
EIFS is available in eight different textures. Hard Coat Stucco is available in a limited variety of sand and freestyle textures,  fully dependent upon the technique skill of the applicator.
EIFS (PB) requires sealant joints at penetrations, at changes in substrate, and at floor lines in wood frame construction.

Hard Coat Stucco requires sealant joints around penetrations, at changes in supstrate, and at floor lines in wood frame construction.

It also requires control joints every 144 square feet, at natural strees points, and any panel areas where the length to width ratio exceeds 2.5:1

EIFS is highly crack resistant and can accommodate building movement. Hard Coat Stucco is typically brittle, and can crack if not propery jointed or cured.