Water is classified as "saline" when it becomes a risk for growth and yield of crops. Saline water has a relatively high concentration of dissolved salts (cations and anions). Salt is not just "salt" as we know it - sodium chloride (NaCl) - but can be dissolved calcium (Ca2+), magnesium (Mg2+), sulfate (SO42-), bicarbonate (HCO3-), Boron (B), and other compounds.
Water can be both saline and sodic, or saline-sodic. If water has an EC greater than 4 (2 for horticulture) and a Sodium Adsorption Ration (SAR) greater than 12, it is considered saline-sodic
If water has a concentration of 10,000 ppm of dissolved salts, then one percent (10,000 divided by 1,000,000) of the weight of the water comes from dissolved salts.