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High and low voltage cables are usually classified with 1kV (1000 volts) as the demarcation point, and they differ significantly in structure, application and safety requirements.

1. Low Voltage Cables
- Voltage Level: Generally refer to cables with a rated voltage of 1kV and below.
- Main Applications: Used for terminal power distribution and connection to electrical equipment.
- Scenarios: Internal power distribution in buildings (such as households, office buildings, factory workshops), household appliances, mechanical equipment, lighting systems, etc.
- Common Types: VV/VLV (polyvinyl chloride insulated and sheathed cables), YJV/YJLV (cross-linked polyethylene insulated and sheathed cables), etc.
- Structural Features: Relatively simple in structure, mainly composed of conductors, insulation layers and sheaths. The insulation layer is usually thin.

2. High Voltage Cables
- Voltage Level: Generally refer to cables with a rated voltage higher than 1kV, commonly including 10kV, 35kV, 110kV, 220kV and above levels.
- Main Applications: Used for long-distance, large-capacity power transmission.
- Scenarios: Main lines of urban power grids, connections between substations, output of large power plants, cross-regional power transmission, etc.
- Structural Features: Complex in structure with multiple layers of protection.
- Conductor: Large cross-section with high requirements for electrical conductivity.
- Insulation Layer: Extremely thick, made of high-quality materials (such as cross-linked polyethylene XLPE) to withstand high electric field strength.
- Shielding Layers: Usually equipped with conductor shielding and insulation shielding layers to uniform electric field distribution.
- Metallic Sheath: Such as aluminum sheath or lead sheath, for waterproofing, moisture-proofing and mechanical protection.
- Outer Sheath: The outermost protective layer.

Core Differences and Selection
In simple terms, low voltage cables serve as the "final segment of power distribution", responsible for safely delivering electricity to each power consumption point; while high voltage cables act as the "main roads of power transmission", responsible for efficiently transporting large amounts of electric energy from power generation ends to power consumption areas. When selecting cables, it is imperative to strictly follow national codes and standards based on requirements such as voltage level, laying environment and current-carrying capacity. In particular, the installation and maintenance of high voltage cables require professional qualifications.