Term: Condensation

The change of state from vapor to liquid. A common factor in moisture damage. Occurs on surfaces, which must be cooler than the air containing vapor next to it. Vapor supply to the condensation surface is usually by airflow but can be by diffusion.

Source: BSD-163: Controlling Cold-Weather Condensation Using Insulation, Info-408: Critical Seal (Spray Foam at Rim Joist)