# Node (graph theory)

In graph theory, a **node** or **corner** is an element of the node set of a graph . If the graph, its node quantity is usually with ( English vertex called). Graphs exist with the node-set or from a corresponding edge set ( English edge ), which describes how the individual nodes of the graph by edges are connected.

## Special knots

- A
**universal node**is a node that is adjacent to all other nodes in the graph . - A
**simplicial node**is a node whose neighbors form a clique , i.e. a complete subgraph of the output graph . - An
**isolated node**in an undirected graph is a node without neighbors, i.e. a node of degree zero. In a directed graph , an isolated node has no predecessors and successors and thus has zero degrees of entry and exit.