| USB 2.0 | USB 3.0 | |
| Released | Apr-00 | Nov-08 |
| Speed | High Speed or HS, 480 Mbps (Megabits per second) | 10 times faster than USB 2.0. Super Speed or SS, 4.8 Gbps (Giga bits per second) |
| Signaling Method | Polling mechanism i.e can either send or receive data (Half duplex) |
Asynchronous mechanism i.e. can send and receive data simultaneously (Full duplex) |
| Power Usage | Up to 500 mA | Up to 900 mA. Allows better power efficiency with less power for idle states. Can power more devices from one hub. |
| Number of wires within the cable | 4 | 9 |
| Standard-A Connectors | Grey in color | Blue in color |
| Standard-B Connectors | Smaller in size | Extra space for more wires |
| Max Cable length | 5 meters | 3 meters |
The USB-C connectors connect to both hosts and devices, replacing various USB-B and USB-A connectors and cables with a standard meant to be future-proof. The 24-pin double-sided connector is slightly larger than the micro-B connector, with a USB-C port measuring 8.4 millimetres (0.33 in) by 2.6 millimetres (0.10 in). The connector provides four power/ground pairs, two differential pairs for non-SuperSpeed data (though only one pair is populated in a USB-C cable), four pairs for SuperSpeed data bus (only two pairs are used in USB 3.1 mode), two "sideband use" pins, VCONN +5 V power for active cables, and a configuration pin used for cable orientation detection and dedicated biphase mark code (BMC) configuration data channel.