Cáp Là Gì? Hiểu Về Cáp và Đầu Nối

## What Is a Cable?

A cable is a physical medium that carries signals — data, video, audio, or power — between two devices. Every cable has at least two **connectors** (the plugs at each end) and a **conductor** (the wire or fiber inside).

## Connectors vs. Cables vs. Standards

These three terms are often confused:

- **Connector**: The physical plug shape (USB-C, HDMI Type-A, RJ45)
- **Cable**: The complete assembly — two connectors joined by wire
- **Standard/Protocol**: The language the devices speak (USB 3.2, HDMI 2.1, Thunderbolt 4)

A USB-C connector can carry USB 2.0, USB 3.2, USB4, Thunderbolt, or DisplayPort — the connector shape doesn't tell you the speed.

## Why Cables Matter

The wrong cable can:
- **Limit your speed**: A USB 2.0 cable on a USB 3.2 port caps you at 480 Mbps instead of 10 Gbps
- **Block features**: A standard HDMI cable won't do 4K@120Hz — you need Ultra High Speed
- **Prevent charging**: Not all USB-C cables support 100W+ Power Delivery

## Key Takeaway

Always check three things: the **connector type** (will it physically fit?), the **standard** (does it support the speed/features you need?), and the **cable certification** (is it rated for that standard?).