A button knot is a knot that forms a bulge of thread.
Button knots are essentially stopper knots, but may be esthetically pleasing enough to be used as a button on clothes.

The single-strand button is a third type of knob knot, in which the working end leaves the knot at the neck, parallel with the standing part, so that the two parts, or ends, together form a stem.
The lay of the two ends is the same, and the knot is symmetrical throughout.

— The Ashley Book of Knots
There are many methods for tying button knots, such as the Chinese button knot, the Celtic button knot and the monkey fist.
The Ashley Book of Knots contains over a hundred examples.
A button knot is a knot that forms a bulge of thread. Button knots are essentially stopper knots, but may be esthetically pleasing enough to be used as a button on clothes.
The single-strand button is a third type of knob knot, in which the working end leaves the knot at the neck, parallel with the standing part, so that the two parts, or ends, together form a stem. The lay of the two ends is the same, and the knot is symmetrical throughout.
— The Ashley Book of Knots
There are many methods for tying button knots, such as the Chinese button knot, the Celtic button knot and the monkey fist. The Ashley Book of Knots contains over a hundred examples.
Button knot