This is the RGB LED matrix panel with 64 WS2812B LEDs arranged in an 8x8 matrix. Each LED is capable of drawing as much as 60mA (at peak brightness the matrix can draw just over 3.5 Amps at 5 Volts), this adds up so it is suggested to use a 5V 2A power supply. For most uses, you'll see about 1-2A of current per panel.
There are two 3-pin connection ports - one for the input signal and another for output signal. A male pin header is soldered to the input port. You can chain as many panels together as you'd like. For the second panel, connect the DIN connection to the first panel's DOUT, connect the ground pins together and power with 5V. It should be noted that after four or more panels you may run low on RAM if you're using an Arduino Uno and you may need a 5V 10A power supply for so many of these!