USB-B vs. USB-C

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.