Cisco USB Console Cable

Some Cisco routers and switches come with a mini USB console port (mini B) in addition to the traditional RJ-45 type console port. To use the USB console port, you will need to download a USB driver from Cisco download site. It is usually hidden under a new router's download section. Here is an example:

 There are different versions of the drivers for 32-bit, 64-bit, and Mac/Linux OS. Once you downloaded and installed the driver, you might need to restart you machine once. When you connect a USB cable to a router's USB console port, your machine will detect the device and add the USB port as a COM port as shown here:

Then you can select correct COM port in Putty or Tere Term and configure your device.
The USB and traditional console port appears as shared port. If you connected to a Cisco router with both connections at the same time, whatever you entered in on terminal session, will show up in the second session.