The third-generation USB interface introduced in 2008.  Called "SuperSpeed USB" (SS USB), USB 3.0 increased speed from 480 Mbps to 5 Gbps and reduced CPU overhead by no longer continuously polling devices.  In practice, USB 3.0 devices do not achieve a 10x speed increase.  For example, a USB 3.0 storage drive may deliver a 50% improvement over its USB 2.0 counterpart.  See 
USB.
A Naming Jumble
USB 3.0 and 3.1 were renamed twice, resulting in the following three ways the same ports may be identified.  Fortunately, this jumble should disappear in the future because a new naming convention was adopted with USB 4 (see 
USB).  See 
USB 3.2.
    USB 3.0            USB 3.1
      3.0                3.1
      3.1 Gen 1          3.1 Gen 2
      3.2 Gen 1x1        3.2 Gen 2x1
A Is Interchangeable; B Is Not
Type A 2.0 sockets accept 3.0 plugs.  But Type B plugs are larger than their 2.0 counterparts.  (Images courtesy of Intel Corporation.)
The Blue Ports
USB 3.0 ports generally have a blue tongue in contrast to black or white, which is USB 2.0.  The SuperSpeed (SS) logos are the primary identifier.
The In-Between Naming
USB 3.0 was USB 3.1 Gen 1 for a while until it was renamed USB 3.2 Gen 1x1.  (Image courtesy of Tripp Lite.)