This cable is easiest way ever to connect to the serial console port of your microcontroller, Raspberry Pi or router. The USB connector contains a USB <-> Serial converter chip and at the other end of the 90cm long cable are four header connectors: red = power, black = ground, white = RX (to USB port) and green = TX (from USB port). The power connector provides 5V @ 500mA directly from the USB port and the RX / TX connectors are 3.3V for interfacing with most 3.3V components.
Because of the separated pin plugs, this cable is ideal for powering and connecting up to the debug/login console on the Raspberry Pi or BeagleBone Black. Connect the pins as shown to power the Pi or BBB and establish the RX/TX link. Then install the CP2102 drivers for Windows/OSX/Linux drivers on your computer and connect with a terminal program at 115200 baud.