1. A closed circuit: A continuous path for the flow of charge. This path can be made of wires, components, or any conductive material.

2. A potential difference (voltage): A difference in electrical potential between two points in the circuit. This difference creates an electric field that drives the charges.

3. Charge carriers: These are particles that carry the electric charge. In most cases, these are electrons, but they could also be ions in a solution or other charged particles.

Here's a simplified analogy:

Imagine a closed pipe filled with water.

* The pipe represents the closed circuit.

* The water represents the charge carriers.

* A pump that creates pressure difference between the two ends of the pipe represents the potential difference (voltage).

The pressure difference caused by the pump drives the water to flow through the pipe. Similarly, the voltage difference drives the charge carriers (electrons) to flow through the circuit, creating electric current.