Condensation refers to water passing from the gas phase to the liquid phase, it happens when temperature drops or when the air is saturated with water.
Crystallization is when the water passes from gas to solid in the form of crystals, for example, when is snowing.
With this information, we can complete the phrases as follows:
The cryosphere is all of Earth's ice. Water can move from Earth's atmosphere to its cryosphere through crystallization.
Clouds form when water vapor forms liquid droplets through condensation.
Both crystallization and condensation happen when energy is low.