The types of solutions outside a cell, relative to the cell's internal environment, are categorized based on their tonicity:

* Isotonic Solution: A solution with the same concentration of solutes as the cell's cytoplasm. There is no net movement of water in or out of the cell.

* Hypertonic Solution: A solution with a higher concentration of solutes than the cell's cytoplasm. Water moves out of the cell, causing it to shrink or shrivel.

* Hypotonic Solution: A solution with a lower concentration of solutes than the cell's cytoplasm. Water moves into the cell, causing it to swell and potentially burst.

Here's a table summarizing the key points:

| Solution Type | Solute Concentration (relative to cell) | Water Movement | Effect on Cell |

|---|---|---|---|

| Isotonic | Equal | No net movement | No change |

| Hypertonic | Higher | Out of the cell | Shrinking |

| Hypotonic | Lower | Into the cell | Swelling |

Examples:

* Isotonic: A saline solution (0.9% NaCl) is isotonic to human red blood cells.

* Hypertonic: Seawater is hypertonic to freshwater fish cells.

* Hypotonic: Pure water is hypotonic to most cells.

Important Note: The specific concentration of solutes that makes a solution isotonic, hypertonic, or hypotonic will vary depending on the cell type.