You can always get the salt out of saltwater by boiling the water away. Two classic examples of mixtures are concrete and salt water. You can see them both being made everyday. Concrete is a mixture of water, sand, and other ground-up rocks and solids. Workers then pour the concrete into a mold and the concrete turns into a solid with the separate pieces inside.
Salt water is a little different.
First, it's a liquid. Now you might be wondering why concrete and salt water are not new compounds when they are all mixed together. The special thing is that the basic parts can still be removed by physical forces. You can take the solid concrete and grind it up again. The individual components can then be separated and you can start all over.