The given picture gives information of a simple water-filter assembly which produces drinkable water.
Looking from an overall perspective, this system consists of two main compartments: one dedicated to the filtration process and the other used for storing clean water.
To begin with, after the lid is lifted, unpurified water is poured into a barrel which contains 3 different layers of materials including sand, charcoal, and gravel. The water then orderly passes through these floors so that the impurities can be thoroughly removed. Once reaching the bottom of the barrel, thanks to the mechanism of the disparity in pressure, the clean water is pumped up through a pipe to the storage drum which is placed in a lower position.
The process continues with the filtered water filling up the storage barrel, awaiting utilization in the future. At the bottom of this container, there is a tap which can be opened to extract drinking water.