Take table salt, sodium chloride, for example.
If you take table salt and dissolve it in water, you are making a salt solution.
Any solution that uses water as the solvent is an aqueous solution. If, for example, you dissolved salt in ethyl alcohol, that would still be a solution but it would not be aqueous.
Now imagine you took salt and heated it really, really strongly and melted it. Just like ice melts to become water, table salt can melt too, just that it's at a much higher temperature. That's a molten liquid. In this case, there is no solvent added.