The substance in which a solute dissolves to form a solution is called the solvent.

Here's a breakdown:

* Solute: The substance that dissolves in the solvent.

* Solvent: The substance that dissolves the solute.

* Solution: The homogeneous mixture formed when the solute dissolves in the solvent.

For example, in a saltwater solution:

* Salt (NaCl) is the solute.

* Water (H₂O) is the solvent.

* Saltwater is the solution.