Here's why:

* Electrons are negatively charged: This charge is the driving force behind electrical current.

* Electrons are loosely bound: In materials like metals, electrons are not tightly bound to individual atoms and can move freely throughout the material.

* Electric fields can influence electron movement: When a voltage is applied, it creates an electric field that pushes the electrons in a specific direction, creating a flow of charge (current).

While protons and neutrons also exist within atoms, they are generally considered stationary within the nucleus and don't contribute to electrical current in the same way as electrons.