To use this cable, simply connect one end to your audio source device, then connect the other end to your audio system or TV.
This cable supports analog stereo audio.
This cable is bi-directional. The 3.5mm connector can be plugged into an audio source, like a smartphone, or to an audio receiver, like a portable speaker. The RCA connectors can also be plugged into an audio source, like a Blu-ray player, or an audio receiver, like a home theater system.
This cable can only be used to pass analog stereo audio. It cable can not be used to converter coaxial S/PDIF to 3.5mm stereo, and it can not be used to convert Mini TOSLINK to stereo analog RCA. Both of those processes would require an active, powered converter.