**Regular Graph**

A graph is said to be regular if every node has the same degree.

*Fig: Regular graph*

**Planar Graph**

A planar graph is a graph that can be embedded in a plane without any edge crossings.

*Fig: Planar graph*

**Maximum Planar Graph**

If a graph is a planar but adding more one edge destroys this property then the graph is called maximum planar graph.

**K-connected graph**

A graph is called K – connected when every pair of vertices are connected and it takes at least k edge failures to disconnect it

*Fig: K-connected graph*