How could people use evaporation and condensation to clean drinking water?

Evaporation and condensation are both phases that water goes through. By allowing the water to evaporate,it will go from a liquid state,to a gas state. Anything that is not water will stay behind. Meaning all impurities will not become a gas like the evaporated water. As the newly formed gas rises into the atmosphere,it will begin to cool down and condense into tiny water droplets. These droplets will then collect into a substantial amount of clean water,making it safe to drink.

By water evaporation from the leaves is created a negative pressure at the top of the tree that promotes the ascension  of the water through channels that are called xylem. there are also two molecule forces that are involved: the intra-water molecules cohesion (water molecules stick to each other) and the adhesion when the water molecules stick to the channels they are running in. this is what enables water to go from the roots to the top of a tall tree.