Junction knots are those nodes which allow to join together different parts that can be ropes rather than piles or artifacts of other gender. These knots are divided into two groups: those performed on strings or ropes of small diameter, which does not necessarily have to dissolve after use; those that are dissolved after use for the recovery of the cable. Generally knots of this type in order to provide security, the peaks that are joined must have the same diameter (with the exception of the flag knot which combines two ropes of different diameters). Some nodes can have a return so as to be easily dissolved in speed.