The USB4 specification (officially known as “USB4,” written without space) has three key traits, according to the USB Implementers Forum (USB-IF). These include:Two-lane operation with up to 40 Gbps operation (over certified cables), using the USB Type-C connection;More efficient sharing between data and display protocols;Backward compatibility with USB 3.2, USB 3.1, USB 3.0, USB 2.0, and even Thunderbolt 3.