neighbor nodes

The nodes that are connected to a given node by a link.

nested graph

A graph that contains nodes that are graphs, that is, a graph that contains nested subgraphs.

node

Another name for a vertex of a graph. In this documentation, the term node is primarily used for vertex.

nonplanar graph

A graph that cannot be drawn without any links crossing other links.

NP-complete

A class of computational problems for which no efficient solution algorithm has been found. Many significant computer science problems, including many graph layout problems, belong to this class.