Adjacent nodes

Two nodes are adjacent within a graph if there exists an edge between them. That is, the two nodes are connected.

Mathematical definition

If a pair of nodes $\{n_1,n_2\}$ exists such that $\{n_1,n_2\}\in E$, then $n_1$ and $n_2$ are called adjacent¹

Footnotes

1. https://en.wikipedia.org/wiki/Graph_(discrete_mathematics) ↩