tip-over

A placement strategy for trees where child nodes are alternately arranged horizontally or vertically.

topology

The structure of a graph. Two drawn graphs have the same topology if you can obtain one drawing from the other by moving the nodes and reshaping the links.

tree

An undirected tree is a connected undirected acyclic graph (that is, a graph that does not contain any cycles). A directed tree is a connected directed graph where each node has exactly one incoming link except the root node, which has no incoming links.