Also known as the Duncan Loop, Gallows Knot, or Grinner Knot.
The Uni Knot has been called the first and last knot you’ll need to learn, due to its universal applicability (and hence the origin of its name). It is a straight forward knot for tying on terminal tackle, and is also the basis for the Uni-to-Uni Knot, one of the fundamental bend knots for joining two lines.
The Uni Knot is somewhat akin to an improved clinch knot tied in reverse, where the loop is tied first then followed by the multiple wraps around the standing line. Despite the universal applicability of the Uni Knot, the Improved Clinch Knot is still favored due to its ease of tying and friendliness to beginners.