A path that goes through every EDGE once and starts and ends at different vertices.
Explanation:
A "Euler path" is a trail that is being used in a graph consisting of finite number of edges. It is also known as "Eulerian path." This should be contrasted from the "Euler circuit," for both of their meanings are a bit confusing.
A Euler path only uses every edge of the graph once and it starts and ends at<em> different vertice</em>s. A Euler circuit, on the other hand, uses every edge of the graph exactly once but <em>starts and ends at the same vertex</em>.
