Question about a cord included with original Super Nintendo game system?

Thanks guys. So my question is, would I get better video or sound if I use this composite cable instead of the RF adapter cord? Also, how do I pull it up if I use the composite cable instead of the RF adapter cord? Do I just change the input instead of going to channel 3, etc.?

That cord is called a Composite cable. Yellow is video, while Red and White are left and right audio channels. Rather than hijacking channel 3 or 4's signal, you'd switch to a different input line on the TV to use these, which gave better signal quality.

However, that type of port was superceded by S-Video, then Component, then HDMI. For the last several years, most TVs have not bothered to have Composite or S-Video ports, though some (probably less than 20%) still support Composite cables using a Component port, plugging the yellow cable into the green video line-in. But for the last year or two, most TVs have completely dropped even Component cable support, opting to only support digital forms of connections.

(Interesting bit of trivia: The SNES, N64, Gamecube (until they removed that port in favor of the Component cables), and old redesign of the NES all shared that exact same cord.)

The multi-out is used to send the audio/video signal from the SNES to your TV. You can use that or the RF Adapter to connect the TV. So no, it's not necessary if you have an RF adapter already, but not all TV setups have a free RF/Coaxial cord since usually it'll be connected to your antenna or cable box or something.