* Homogeneous mixture: A mixture where the components are evenly distributed throughout. You can't visually distinguish the different parts.

* Heterogeneous mixture: A mixture where the components are not evenly distributed. You can see distinct parts.

When you dissolve salt (NaCl) in water, the salt crystals break down into individual ions (Na+ and Cl-) that are evenly dispersed throughout the water molecules. You can't see the salt particles anymore, and the entire solution appears uniform.