A solution is nothing but a mixture. It is a homogeneous mixture of one or more solutes and a solvent. A solvent is the component of a solution that is abundant and in which the solutes get dissolved. In contrast, a solute is the component of a solution that is dissolved in the solvent to form a solution. The amount of solute that can be dissolved in a solvent is known as the solubility of a solution.

In our everyday life, we use numerous solutions. But, do we know if it is a solution? For example, colloids and types of colloidal solution seem like a solution to naked eyes. But, they are heterogeneous mixtures and not solutions. There are also some unique solutions like Buffer solution and different types of Buffer solution. Based on several factors, there are different types of solutions. 

Types of solution depending on the nature of the solvent

Depending on the nature of the solvent, the solutions are classified into two types: 

1. Aqueous solutions- These solutions are the solutions formed when a solid is dissolved in water. Some examples of aqueous solutions are detergent in water, salt in water, and sugar in water. 
2. Non-aqueous solutions- When a solid is dissolved in a liquid that is not water, it forms a non-aqueous solution. In these solutions, the solvent can be liquids like alcohol, benzene, acetone, carbon disulphide, etc. 

Classification of solution based on the concentration

The concentration factor classifies solutions into two types of solution:

1. Concentrated solutions- When a solution contains high solute concentration in a given amount of solvent, it forms a concentrated solution. Brine solution dark-colored tea is some of the numerous examples of these solutions. 
2. Diluted solutions- Opposite to concentrated solutions, diluted solutions are the solutions that contain large amounts of solvent and less amount of solute. A salt solution is an example. 

Types of solution depending on the concentration of the solution in two solutions

For understanding this classification, the best way is to assume a cell immersed in a solution in a beaker.

1. Isotonic solution- In isotonic solutions, the solute concentration is the same in both cells and the solution in the beaker. Therefore, the water moves in both directions- into and out from the cell. 
2. Hypotonic solutions- Such kinds of solutions contain lower amounts of solute in the solution in the beaker. Hence the water moves into the cell and causes it to swell. 
3. Hypertonic solutions- In a hypertonic solution, the solute concentration is more in the solution in the beaker. Therefore, the water comes out of the cell and shrinks it. 

Types of solution depending on the solute’s amount added.

Another factor for classifying solutions is the amount of solute added to a solution. 

1. Unsaturated solutions- Unsaturated solutions are the solutions in which more solute can be added and dissolved without increasing its temperature. In other words, these solutions contain less solute than the maximum amount of solute that can be dissolved at a particular temperature. 
2. Saturated solution- A saturated solution is a solution in which the maximum amount of solute that can be dissolved at a temperature has been dissolved, and no further solute can get dissolved. 
3. Supersaturated solutions- Supersaturated solutions are the types of solution that contain more solute than the maximum amount that can be dissolved at a temperature. 

Types of solution based on the physical states of solute and solvent

Solutions can be made with any state of solute and solvent. Hence, based on the physical states of solutes and solvents, the solutions are nine types. 

1. Solid in solid solutions- The name speaks for itself; both solute and solvent are solids. Example- alloy
2. Liquid in solid- In these types of solution, a liquid solute is dissolved in a solid solvent. Example- Hydrated salts
3. Gas in solid- This solution has a gaseous solute in a solid solvent. Example- H2 in Pd
4. Solid in liquid- It has a solid solute in a liquid solvent. Example- salt in water
5. Liquid in liquid- Both solute and solvent are liquid in such solutions. Example- Methanol in water
6. Gas in liquid- It has a gaseous solute dissolved in a liquid solvent. Example- aerated drinks
7. Solid in gas- It has solid solute and gaseous solvent. Example- Iodine vapor in the air
8. Liquid in gas- It has liquid solute in a gaseous solvent. Example- humidity in the air
9. Gas in gas- Both solute and solvent are gaseous. Example- Air

Conclusion

The solution is a homogeneous mixture of solute and solvent. There are numerous types of solutions based on several factors. The solute particles in a solution are so small that they cannot be seen even with a microscope. Also, if a solution is passed through a filtration paper, the solute particles do not get filtered out. One of the numerous characteristics of a solution is that they do not scatter light.