What are knots in aid of?

Knots are used for fastening. With knots, ropes can be connected to one another or fastened directly to objects. Objects are connected by nodes. Over thousands of years, there was hardly a life where knots did not fulfill important functions: housebuilding, hunting, cattle-farming, fishing, everywhere knots were needed.
The knowledge of knots was of great importance. Today, other techniques are often used for fastening, but knots are even more often used in professional use than you would expect.
In the course of many leisure activities you learn a simple usage knots: for example, a knot test for the sailing license, also with climbing and fishing knots are very important.