Here's why:

* Dissolved Ions: Saltwater contains dissolved ions (charged particles) like sodium (Na+) and chloride (Cl-) ions. These ions are free to move, allowing electricity to flow through the solution.

* Electrolyte: Saltwater is an electrolyte, meaning it contains ions that can carry an electrical current.

* Conduction Mechanism: When a voltage is applied across saltwater, the ions move towards the oppositely charged electrodes. This flow of charged particles constitutes an electric current.

In contrast, pure water is a very poor conductor of electricity because it lacks free ions. However, the presence of even a small amount of dissolved salts dramatically increases its conductivity.