Voltage, also known as (electrical) potential difference, electric pressure, or electric tension, is the difference in electric potential between two points.
The electric potential difference applied to network cables and devices to ensure proper signal transmission and power delivery. Voltage is crucial for maintaining signal integrity and the functioning of Power over Ethernet (PoE) systems, where specific voltage levels are required to power network devices such as IP phones, IP cameras, and wireless access points through Ethernet cables.