2. 1. A hierarchical net; a multilevel data structure. It consists of a number of entities in “from top down” relationships and a specification of the orders in which they can be accessed. The entity of highest position (the entity that must be accessed first in order to access any other entity in the structure) is the root (also origin).The other entities of the structure are owners and members; they are connected for access purposes by pointers which may also be termed links, connectors, or relationships.
