It is basically as solution of salt and water. There are many concentrations of "saline solution" the most common of which is "normal saline" which is 0.9% sodium chloride (NaCl) in water. Saline...
0.9% NaCl solution (normal saline, physiological saline) is used to give intravenous fluids to the patients suffering from salt and water deprivation. It can be used to wash the wounds etc.