Appearance
Polished concrete has a natural stone-like look and shows the aggregate in the slab. Epoxy is a coating — solid color, flake, or metallic — and hides slab imperfections.
Durability
Polished concrete is the slab itself — extremely durable but can stain from oil and acids. Epoxy is a sacrificial layer that protects the slab and resists chemicals.
Cost
Polished concrete typically runs $5–$10 per square foot; epoxy systems run $5–$18 depending on complexity. For similar visual quality, epoxy is often lower cost.
Maintenance
Polished concrete needs periodic re-densifying and burnishing. Epoxy needs occasional cleaning and a refresh topcoat every 7–10 years.