USB发展史：从1.0到USB4

## 1996: USB 1.0 — The Beginning

USB was created by a consortium of seven companies (including Intel, Microsoft, and IBM) to replace the mess of serial, parallel, and PS/2 ports on PCs. USB 1.0 ran at just 1.5 Mbps.

## 2000: USB 2.0 — The Mass Adoption

At 480 Mbps, USB 2.0 was fast enough for printers, cameras, and early MP3 players. It became the universal port. The familiar USB-A and Mini-B connectors dominated.

## 2008: USB 3.0 — SuperSpeed

A 10x speed jump to 5 Gbps. Blue-tipped USB-A connectors distinguished 3.0 from 2.0. External hard drives finally became practical for large file transfers.

## 2014: USB Type-C Connector

The reversible USB-C connector launched — no more flipping the plug three times. It could carry USB 3.1, DisplayPort, power delivery, and eventually Thunderbolt.

## 2019: USB4 — Merging with Thunderbolt

Intel donated the Thunderbolt 3 protocol to the USB-IF, creating USB4. 40 Gbps, tunneling for DisplayPort and PCIe, and mandatory USB-C.

## 2022: USB4 v2.0 — 80 Gbps

Doubling to 80 Gbps (with asymmetric mode reaching 120 Gbps for displays). The line between USB and Thunderbolt continues to blur.