USB

Micro-USB (Micro-B) was the dominant charging and data connector on non-Apple smartphones and small electronics from the late 2000s through the mid-2010s. Its USB 3.0 variant added a second, wider tab beside the standard 5-pin plug for extra SuperSpeed pins -- a design most phone makers skipped, keeping plain USB 2.0 Micro-B nearly universal in practice.

Mini-USB (Mini-B) was a compact 5-pin connector common on digital cameras, MP3 players, and the original PlayStation Portable in the mid-2000s. USB-IF deprecated the Mini connector family in May 2007, and Micro-USB replaced it in nearly all subsequent compact-electronics designs.

USB 1.1, released in September 1998, was the first widely adopted USB standard -- 12 Mbit/s Full Speed for most peripherals, with a 1.5 Mbit/s Low Speed mode for mice and keyboards. The original USB 1.0 from January 1996 saw little real-world adoption before 1.1 quickly superseded it.

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.

Originally released as USB 3.0 in November 2008, this 5 Gbit/s "SuperSpeed" tier was retroactively renamed USB 3.2 Gen 1x1 when the USB 3.2 specification arrived in 2017 -- the first step in a naming scheme many found more confusing than clarifying, since the underlying hardware and speed never actually changed.

Originally released as USB 3.1 in July 2013, this 10 Gbit/s tier used more efficient 128b/132b encoding than USB 3.0's 8b/10b. It was renamed USB 3.2 Gen 2x1 in 2017 alongside USB 3.0's rename to Gen 1x1 -- both generations kept identical real-world hardware, with only the marketing name changing.

USB 3.2 Gen 2x2, part of the USB 3.2 specification released in September 2017, is the only tier in the 3.2 family that's genuinely new hardware rather than a renamed predecessor -- it doubles Gen 2's 10 Gbit/s by running two lanes simultaneously, reaching 20 Gbit/s, but only over USB-C connectors and cables wired for it.

USB Power Delivery (USB PD) is a separate negotiation protocol governing how much power flows over a USB-C cable -- independent of the cable's data speed. Standard Power Range tops out at 100W (20V/5A); PD 3.1's Extended Power Range (2021) raised that ceiling to 240W (48V/5A), requiring cables with a built-in identification chip.

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.

USB-B (Standard-B) is the squarish connector historically used on printers, scanners, and external hard drives -- the peripheral-side counterpart to USB-A. A 9-pin SuperSpeed variant with a distinctive stacked upper tab was added for USB 3.0, though USB-C has since displaced Standard-B in most new peripheral designs.

USB-C is the reversible, oval 24-pin connector now used across USB 2.0 through USB4 and Thunderbolt. It's the only connector required for USB4, and under EU law it became mandatory on most new phones, tablets, and cameras sold in the EU by the end of 2024, with laptops following by April 2026.

USB4, released August 2019, is built on Intel's Thunderbolt 3 protocol, donated to USB-IF as the new foundation -- up to 40 Gbit/s, a mandatory USB-C connector, and tunneling that lets a single port carry USB, DisplayPort, and PCIe traffic at once. Thunderbolt 3 compatibility is required; Thunderbolt 4 compatibility is optional for device makers.

USB4 2.0, released September 2022, doubles USB4's ceiling to 80 Gbit/s symmetric -- or an asymmetric 120/40 Gbit/s split favoring one direction for high-bandwidth uses like external displays. It requires new cables explicitly rated for the higher speed; existing USB4 v1 cables aren't guaranteed to reach it.