The global population has grown significantly over the past 50 years. Quality of life is generally increasing, along with the higher need for energy and water, alongside the proliferation of environmental issues to be resolved. High-quality drinking water is essential for day-to-day living, for food production, for better living standards, for the somehow neglected nature and for industry. The need for water is increasing rapidly and freshwater resources cannot deal with all of the requirements. Water is not accessible to all as a natural, self-renewable low-cost resource. Droughts in various regions on earth followed by "desertification" and the gravitation of populations towards this "essence of life" are calling for different considerations in terms of economic and social effects. This article summarizes the main techniques that survived and those that did not. Explanations regarding the physics and chemistry of the different processes are provided. The different modes of operation are given along with the criticisms. An analysis of new developments in the area is also presented. The different techniques, trends, economy, environmental and energy aspects, as well as other significant parameters associated with the state-of-the-art of modern desalination and other possible water resources are discussed here.