Lets see this with example
if you put a red blood cell in a glass of water the red blood cell is in hypotonic solution and that water flows into less concentrated area ( in to the red blood cell ) which eventually will swell and burst.
Another plot is when we put the same red blood cell in a glass full of salty solution which is Heterogeneous solution. In these case the water will move out from the cell to the solution which cause the cell to shrink.