Channel setting is a method whereby stones are suspended between two bars or strips of metal, called channels. Often when setting small stones and the bars go in a linear line with the design it is called channel setting, and when the bars cross the lines of the design, it’s called bar set. The idea is the same, though. The channel is some variation of a “U” shape, with 2 sides & a bottom.
In a channel setting, there’s no metal separation between each diamond. Instead, the stones are set next to each other in a groove inside the ring. This style is popular for eternity bands that use channel-set diamonds to cover the circumference of the ring.

other settings:
prong   bezel   pave