Node definition may depends on the network and protocol layer referred to.
A passive distribution point such as a distribution frame or patch panel is consequently not a Node.
A Node is a Data Structure which may contain a value or condition, or represent a separate data structure (which could be a tree of its own). Each Node in a tree has zero or more child nodes, which are below, or inferior, it in the tree (by convention, trees are drawn growing downwards).
A Node that has a child is called the child's parent node (or superior ). A node has at most one parent, but possibly many ancestor nodes, such as the parent's parent. Child nodes with the same parent are sibling nodes.