A heterogenous mixture is basically any mixture ( liquid, solid or gas ) whose parts are not homogeneous meaning, it is composed of smaller constituent parts that can be separated and differentiated from the others. Conversely, in the homogeneous mixture the individual parts are not differentiable and uniformly distributed along the mixture. The composition of said mixture is the same throughout, and therefore has only one phase of mater so you wont find any solids nor gases in a liquid homogeneous mixture, like you would find on a heterogenous one.
