Potable describes water that is clean and safe to drink, meeting standards for microbiological, chemical, and aesthetic quality. Potability is defined by regulation: the WHO Guidelines for Drinking-water Quality and national standards like the EU Drinking Water Directive set limits for pathogens (essentially zero E. coli), nitrates, lead, pesticides, and dozens of other parameters. Achieving it requires source protection, treatment through filtration and disinfection, and distribution systems that prevent recontamination. In food manufacturing, potable water is the legal minimum for ingredient water, handwashing, and equipment cleaning, with higher purities specified for particular processes. Globally, nearly two billion people still lack safely managed drinking water, and waterborne disease remains a leading killer of children, making potability one of public health’s most fundamental and unfinished tasks.