Water is often called the universal solvent, but that's not entirely accurate. While it's true that water dissolves a wide variety of substances, it's not a true universal solvent.

Here's why:

* Not all substances dissolve in water. For example, oil and fat are hydrophobic (water-repelling) and don't dissolve in water.

* There are other solvents that dissolve more substances than water. For example, acetone is a good solvent for many organic compounds, even some that water doesn't dissolve.

So, while water is an excellent solvent and dissolves many substances, it's not truly universal.