The clouds' contribute to environmental system is enormous; clouds can produce solid and liquid water though a series of physical phenomena that take place at different spacial scales. The presence or absence of clouds is essential for many weather aspects. The understanding of both the chemistry and physics of clouds can lead to a wider knowledge of the chemistry and physics of real-world phenomena. Clouds' processes take place at different spacial scales, the phenomena that occur at the micro scale are non generally visible to human eye. Humans see the macroscopic scales, the net consequence of the light, coming from the sun, scattered by the presence of water drops and small ice crystals inside clouds.