Well, the PSC's are digital coaxial cables, so we can merge those two together. They are also suitable for composite and component video applications. That is because the PSC cables are rated for 75 ohms, which is critical for video signals and digital audio signals. The PCA's are a more standard analog audio cable, which does not have to adhere to that 75 ohm requirement. You can use PSC's for composite video, component video, analog audio, or digital audio, but the PCA's really should only be used for analog audio.