What is the difference between filmwise and dropwise condensation?

Filmwise condensation forms a continuous liquid film on the surface that acts as thermal resistance between vapor and surface - heat transfer coefficient is typically 5,000-15,000 W/m2K. Dropwise condensation forms discrete droplets that roll off, exposing fresh surface - heat transfer can be 5-10x higher but is difficult to maintain as surfaces eventually wet. Dropwise condensation is promoted by surface coatings (PTFE, silicones) or surface treatments, but industrial designs typically assume conservative filmwise condensation.