Desalination is the process of removing salt and other impurities from seawater or brackish water to make it suitable for human consumption, agriculture, or industrial use. It's especially important in arid regions or areas facing freshwater scarcity. The most common methods include reverse osmosis, which uses semi-permeable membranes, and thermal distillation, which involves heating water to separate salt. While desalination provides a reliable source of freshwater, it can be energy-intensive and poses environmental concerns related to brine disposal. Advances in technology are helping make desalination more efficient and sustainable.