Editing Regular graph (section)

==Special cases==
Regular graphs of degree at most 2 are easy to classify: a {{nowrap|0-regular}} graph consists of disconnected vertices, a {{nowrap|1-regular}} graph consists of disconnected edges, and a {{nowrap|2-regular}} graph consists of a [[disjoint union of graphs|disjoint union]] of [[cycle (graph theory)|cycle]]s and infinite chains.

A {{nowrap|3-regular}} graph is known as a [[cubic graph]].

A [[strongly regular graph]] is a regular graph where every adjacent pair of vertices has the same number {{mvar|l}} of neighbors in common, and every non-adjacent pair of vertices has the same number {{mvar|n}} of neighbors in common.  The smallest graphs that are regular but not strongly regular are the [[cycle graph]] and the [[circulant graph]] on 6 vertices.

The [[complete graph]] {{mvar|K{{sub|m}}}} is strongly regular for any {{mvar|m}}.

<gallery class="skin-invert-image">
Image:0-regular_graph.svg|0-regular graph
Image:1-regular_graph.svg|1-regular graph
Image:2-regular_graph.svg|2-regular graph
Image:3-regular_graph.svg|3-regular graph
</gallery>