Here's why:

* Electric Current: Electricity is the flow of electric charge.

* Electrons as Charge Carriers: Electrons carry a negative charge. In materials like metals, some electrons are loosely bound to their atoms and can move freely throughout the material.

* Conduction: When a voltage is applied across a conductor, the electric field created by the voltage causes these free electrons to drift in a specific direction, creating an electric current.

Therefore, the presence of freely moving electrons allows materials to conduct electricity.