These lower level nodes are also connected to a single or multiple nodes in the next level down .
The type of network topology in which an central ` root ' node ( the top level of the hierarchy ) is connected to one or more other nodes that are one level lower in the hierarchy ( i.e. , the second level ) with a point-to-point link between each of the second level nodes and the top level central ` root ' node , while each of the second level nodes that are connected to the top level central ` root ' node will also have one or more other nodes that are one level lower in the hierarchy ( i.e. , the third level ) connected to it , also with a point-to-point link , the top level central ` root ' node being the only node that has no other node above it in the hierarchy ( The hierarchy of the tree is symmetrical . )