The FTDI USB to TTL breakout board is a USB to Serial (TTL) which makes it fast and easy to connect devices with a TTL level serial interface to USB.
It is based on the standard FT232RL chipset. This board is configured to operate at 5V.
It now uses a SMD 6-pin header on the bottom, which makes it smaller and more compact. Functionality has remained the same.
This is a basic breakout board for the FTDI FT232RL USB to serial IC. The pinout of this board matches the FTDI cable to work for Arduino and cloned for 5V for Arduino boards. It can also be used for general serial applications. The major difference with this board is that it brings out the DTR pin as opposed to the RTS pin of the FTDI cable. This is a really nice feature to have and allows a sketch to be downloaded without having to hit the reset button. This board will auto reset any for Arduino board that has the reset pin brought out to a 6-pin connector.
The pins labeled BLK and GRN correspond to the colored wires on the FTDI cable. The black wire on the FTDI cable is GND, green is CTS. Use these BLK and GRN pins to align the FTDI basic board with for Arduino target.
This board has TX and RX LEDs that make it a bit better to use over the FTDI cable. You can actually see serial traffic on the LEDs to verify if the board is working.