Today I've learnt a lot about different knots. One of them was figure 8 knot - most commonly used in climbing community if we need a simple and quick solution to anchor the rope to a point. Another one was a "butterfly" which has a similar function to figure 8 but is more diverse. For example, we can have multiple butterfly knots on one rope and use them. With figure 8 knots - not really as the rope breaking load decreases too much.