Vinyl tubing refers to a flexible tube made from a plastic material called vinyl. It is commonly used to transport liquids or gases from one place to another. Full definition
Jumper Tubing: The flexible piece of vinyl tubing that is used between the keg and draught beer system that should be replaced annually. (draughtquality.org)
Tip: I usually push a 3/8» clear vinyl tube over the bleeder screw so that I can better oberve the color of the fluid and see bubbles in the tubing as I bleed the brake line. (mechanics.stackexchange.com)