Sodium chloride is ordinary table salt, having the chemical formula NaCl.
Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multicellular organisms. Sodium chloride is frequently termed common salt or table salt.
Sodium chloride is essential for life. Humans are unusual amongs primates in secreting large amounts of salt by sweating.
Salt is produced by evaporation of seawater or brine from other sources, such as brine wells and salt lakes, and from mining rock salt.
0.9% solution of sodium chloride in water is called physiological because it is isoosmotic with plasma. Saline can be prepared by dissolving 0.85 gram of sodium chloride in 100 ml of distilled water. Physiological solution is the mainstay of fluid replacement therapy that is widely used in medicine in prevention or treatment of dehydration.