What is the essence of the principle of vassal dependence?

A vassal is a person who, in exchange for land, performed a certain service or work for a senior feudal lord. Vassal dependence consisted in the fact that a person was a vassal associated with another, senior feudal lord over him. The vassal pledged to serve the feudal lord for a certain period of time.
Later, vassalage became quite common that there was a statement “the vassal of my vassal is not my vassal”



One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.