Endless and flemish are two different types of methods for making strings.
Endless is the one you will see that has serving on both ends and the middle. Hints the name "endless". It is made by continually wrapping material around posts stretched out at the necessary length to make the desired string length.
Flemish is made by making a bundles and twisting them together with a twist away and a roll towards. Most people say a flemsih is quieter than endless. I would speculate that that's because and endless loop doesn't have as many many twists ni it and would absord less vibration than an flemish twist.
(the silencing part was all opinion, so don't put too much weight on those.)