* Hypertonic: A hypertonic solution has a higher concentration of solutes (like salts) compared to the inside of the cell. This causes water to move out of the cell (following the concentration gradient) in an attempt to dilute the higher solute concentration outside.

* Isotonic: An isotonic solution has the same concentration of solutes as the inside of the cell. There is no net movement of water in or out of the cell.

* Hypotonic: A hypotonic solution has a lower concentration of solutes than the inside of the cell. This causes water to move into the cell, making it swell.

In summary: If water is flowing *out* of the cell, it means the solution surrounding it has a higher solute concentration, making it hypertonic.