* Homogeneous mixtures have a uniform composition throughout. This means the components are evenly distributed and you can't visually distinguish them.

* Heterogeneous mixtures have components that are not evenly distributed. You can often see the different parts of the mixture.

When you dissolve sugar in water, the sugar molecules become evenly dispersed throughout the water. You can't see the individual sugar molecules, and the solution appears clear. This indicates a uniform composition, making it a homogeneous mixture.