Sublimation is the phase transition in which a solid instantly transforms into a gas. When a substance's temperature and pressure are such that the solid phase can transition directly to the gas phase without first going through the liquid phase, this is known as sublimation. In contrast to deposition, which skips the liquid phase and converts a gas directly into a solid, this process does the opposite.
In nature, sublimation occurs often and may be seen in a number of settings. For instance, under ambient temperature and pressure, dry ice (solid carbon dioxide) sublimes to create a gas that is frequently employed in special effects and for food preservation. Similar to this, under some circumstances, snow and ice may sublimate and release water vapor.