An **Euler Trail** is a trail that visits every edge exactly once.

A **Euler Trail** exists in a graph iff there are only two vertices of odd degree.

If a graph has more than 2 vertices of odd degree then it has **no Eulerian trail**.

To find an Euler trail in a graph using Fleuryâ€™s Algorithm, start from an **odd** degree vertex and finish on an **odd** degree vertex.