USB hardware

The initial versions of the USB standard specified connectors that were easy to use and that would have acceptable life spans; revisions of the standard added smaller connectors useful for compact portable devices. Higher-speed development of the USB standard gave rise to another family of connectors to permit additional data links. All versions of USB specify cable properties; version 3.x cables, marketed as SuperSpeed, added a data link, namely in 2008 USB 3.0 added a full-duplex lane (two twisted pairs of wires for one differential signal of serial data per direction). In 2014 the USB-C specification finally added a second full-duplex lane.

The USB standard always included power supply to peripheral devices; modern versions of the standard, defined by the dedicated USB Power Delivery-specifications (USB PD 1.0, since 2012), allow power delivery up to 60 Watts (USB PD 1.0), or up to 100 W (USB PD 2.0 ver. 1.2, 2013; together with USB 3.1), or up to 240 W (since USB PD 3.1, 2021), for battery charging and powering various devices. USB has been selected as the charging format for many mobile phones and other devices, reducing the proliferation of proprietary chargers.