In the last 40 years, the problem of freshwater shortage has been one of the main challenges in the world. Potable water not only is important for life but also for industrial and agricultural purposes. So, the life without water will be impossible. The origin and continuation of mankind is based on water. Although more than 75% of the earth covered with water, only 0.014% of that can be used directly for the human being and other organisms. On the other hand, sea water constitutes 97.5% of global water, so it can be used for those purposes by converting it to distilled wate. There are some techniques for water purification, which among them, solar water distillations is an attractive subject. A single basin solar still is a very simple solar device used for converting available brackish or waste water into potable water. The solar distillation systems are mainly classified into two categories: passive and active solar still. In passive solar stills, solar radiation is the only parameter which affects evaporation, but in active solar stills by using the additional device such as fan, pump, sun tracking system or solar collectors and the temperature difference between evaporating and condensing area is increased, and consequently enhancement on productivity is achieved.