Question

what are isotonic and hypertonic solution

Answer 1

Isotonic solutions are those which have the same amount of solute (proportionally) with respect to the cell. When a cell is placed here, there is no net movement of water as equal amounts move in and out.
Hypertonic solutions are those which have more solute and less water with respect to the cell. If a cell is placed here, the cell will lose water and shrink. This is called plasmolysis in a plant cell. 

Answer 2

Isotonic- The relative concentration of water molecules and the solution either side of the cell membrane is the same. Thus,there is no movement of water molecules,hence no osmosis.
Hypertonic- In this condition,the solution outside the cell has a higher solute concentration than the fluid inside the cell, consequently,the water molecules from the interior of the cell will move out (exosmosois)