* Compound: A compound is formed when two or more elements chemically combine in a fixed ratio. The resulting compound has properties distinct from the original elements. For example, water (H₂O) is a compound made of hydrogen and oxygen.

* Mixture: A mixture is a combination of two or more substances where each substance retains its own individual properties. The components of a mixture can be separated by physical means.

Salt solution: A salt solution is formed when salt (NaCl) dissolves in water (H₂O). While the salt dissolves and appears to disappear, the salt molecules are still present in the solution. The salt and water retain their individual properties. You can separate the salt from the water by evaporating the water.

Therefore, because the components of a salt solution can be separated and retain their individual properties, it is classified as a mixture.