The USB.3 port as the fastest port among Universal Serial Bus interfaces are usually colored blue in new PCs (not always) to differentiate them from older version USB 2.0 ports. The transfer rate of USB 3.0 is 5 Gb/s, although this throughput is never exactly achieved.
Since many devices themselves are not able to reach to that level of throughput, like spinning hard disks. eSATA has also been considered as a professional interface, since it has been designed to work with hard drives primarily.