* Homogeneous Mixture: A mixture where the components are evenly distributed throughout and have a uniform composition. You can't easily distinguish the different parts.

* Heterogeneous Mixture: A mixture where the components are not evenly distributed and you can see the different parts.

Spring water contains various dissolved minerals and gases, but these are evenly distributed throughout the water. You can't see or separate them easily. Therefore, it's considered a homogeneous mixture.