A homogeneous solution seems to be one substance to the naked eye but actually it is a mixture of molecules of two or more substances at particle level.Each fraction of the solution is uniform and contains same quantity of molecules as the entire solution. Therefore, there is homogeneity at the particle level in a homogeneous solution.
Eg:
NaCl solution is a homogenous solution.Each fraction of this solution is uniform and contain same quantity of Na and Cl atoms at the entire solution.