How is the melting point of a substance related to its freezing point?

If you heat up a solid compound, its temperature will rise. At a certain temperature, it will start to melt, and the temperature will stay constant untill it's all liquid; only then it will rise further. Cooling that same liquid will lower the temperature, untill it reaches exactly the same temperature. And then it will start to solidify, while -again- the temperature stays constant untill all of it is solid.

Mixtures of compounds will have a melting and solidifying range of temperatures.

The temperature at which a substance's liquid and solid phases coexist in equilibrium is known as the substance's melting or freezing point, and they are the same.

The melting point and freezing point of a substance are the same temperature, as they represent the temperature at which the substance transitions between solid and liquid states.