The water cycle (hydrologic cycle) is the continuous movement of water on, above, and below the surface of the Earth. Key processes include evaporation (liquid water changing to vapor), condensation (water vapor changing to liquid or solid), precipitation (water falling from clouds as rain, snow, etc.), infiltration (water soaking into the ground), runoff (water flowing over the land surface), and transpiration (water released by plants). Composition refers to the make-up of something (e.g., water's composition is H₂O); it is not a process within the water cycle.