This is an inexpensive HDMI cable that you can use to hook up your Raspberry Pi to a suitable monitor or TV. Heck, you can hook up anything you want with it, HDMI is becoming more and more common as a digital audio/video standard.
RCA cables are super handy for moving analog signals around. This is a great way to connect a composite video capable device, like the Raspberry Pi, to a suitable display. They also come in handy if you want to hook up your old-school analog gaming consoles, you know it’s always impossible to find an RCA cable when you’re hooking up the NES for some Tetris.
This HDMI to VGA Adapter enables you to connect an HDMI port to a VGA port. These adapters are especially useful for displays or monitors that only use VGA ports so they can be used with HDMI devices like the pcDuino or Raspberry Pi. Each adapter comes with a 3.5mm jack cable for audio output.