The red end wih an arrow indicates that it's a gozinta. As in it gozinta the downstream equipment. The other end is the gozouta, where the volts gozouta the upstream device.
Whether it matters or not is subject of hot debate between the earnestly misguided and the quacking hucksters on one side, and the physical realists on the other. Cables can matter, just usually not for the reasons and quasi-theories promulgated, and not as much as claimed.
See also Placebo Effect and Confirmation Bias.