What is the difference between freshwater and saltwater, with examples?

This is a very interesting question. There are four angles from which the question can be answered.
I) Chemical composition: Fresh water is considered to be water that contains less than 1% of salt. This is because both fresh and salty water contains some level of salt. The big difference is that the concentration of salt in saltwater is higher than that of fresh water. The common types of salt found in natural water bodies include Sodium Chloride(NaCl), Sodium Bicarbonate(NaHCO3) and Magnesium Chloride( MgCl2) among others. Seawater has high concentrations of Sodium Chloride and Sodium Bicarbonate. On the other hand, freshwater bodies do not contain Sodium Bicarbonate in significant amounts.

II) Density and buoyancy: Since salt is dissolved in water, saltwater has a higher density than freshwater. This makes saltwater more buoyant than freshwater. For example, When you swim in seawater, you will find it easier to float than when you swim in freshwater.

III) Electric Conductivity: Saltwater is a better electrical conductor than freshwater. The salt in the water is usually in dissolved form and exists as ions. Since saltwater has more ionic concentration, it is a better electrical conductor than freshwater. However, freshwater can also conduct electricity to some extent.

IV) Life Support: Both saltwater and freshwater support different species of flora and fauna. However, the species that thrive in saltwater do not stand a chance of life in freshwater. Each ecosystem is well designed to host the specific species. If you take a saltwater fish and place it in freshwater, the fish will not survive. Saltwater cannot be consumed by humans. It is highly toxic and more often acidic. Summary -Saltwater has a salt concentration of more than 1% while freshwater has a concentration of less than 1%. -Saltwater has a higher electrical conductivity than freshwater. -Saltwater is denser and more buoyant than freshwater.

There are many differences between freshwater and saltwater. The most obvious difference is that saltwater contains salt, or sodium chloride. Freshwater does contain a small amount of salt as well, but not enough to be considered saltwater. To be considered freshwater, the body of water must contain less than 1% salt. The salt lends itself to other differences between freshwater and saltwater. For example, because of the salt dissolved in saltwater, saltwater is also more dense than freshwater. This means the volume of the water is heavier than that of freshwater. What is interesting about this difference is that it means saltwater is also more buoyant than freshwater. This means in bodies of water with a high concentration of salt, you can nearly float! The salt in saltwater also alters the freezing point. Saltwater has a lower freezing point than freshwater because of the salt in it. Another difference concerns the animals that can survive in each body of water. Typically, most animals can only live in one or the other environment, not both.