The significance of comprehending microbial life and adaptation within the framework of sustainable development is of utmost importance for the betterment of human life. Microbes are the smallest life forms inhabiting our planet, and wield substantial influence in upholding ecological equilibrium and bolstering human well-being. They play important role in fulfilling the various sustainable goals such as good health and well-being, affordable and clean energy, biotechnological applications and innovations, agricultural production and food industry innovation, and climate control. In this chapter, we have unveiled the life and adaptation of microbes in different environments, i.e., land, underwater, and on other planets and moons, and how they play a significant role in sustainable development. The chapter includes various aspects and application of microbes and microbial biotechnology in the diverse terrestrial and aquatic ecosystems. It also provides in-depth information of microbial adaptation and progress in astrobiology and microbial life beyond the Earth.