what is meant by saturated solution?

Answer 1

All of a substance (i.e. salt) that can be dissolved in a liquid (i.e. water) is dissolved in that liquid. You have to keep adding salt to water and stirring until no more salt can dissolve into the water, no matter how much you stir. There will be a few salt crystals at the bottom.

Answer 2

A liquid has a certain capacity of supporting a dissolved substance. Above that level and the substance will precipitate out. The point of saturation is the maximum amount of the substance that will be supported in solution.