USB 2.0 vs. USB-A

USB 2.0, released in April 2000, added a 480 Mbit/s High Speed mode on top of USB 1.x's rates -- a 40x jump that made USB viable for external hard drives and other high-throughput peripherals for the first time. It remains the fallback data rate on many budget cables and low-power devices today.

USB-A (Standard-A) is the flat rectangular connector on host ports -- computers, chargers, hubs. It used 4 pins for USB 1.x/2.0 speeds; a 9-pin variant, adding 5 SuperSpeed contacts, extended it to USB 3.0+ in 2008 without changing the external shape or requiring a new socket design.