Other contributors have said "What end of the circle does a euler circuit touch?" is the same question as "What is a Euler path or circuit?" If you believe that these are not asking the same thing and should be answered differently, click here
Generally, a circuit with multiple paths is called "parallel" because of the structure of the wiring involved. Parallel circuits have identical voltage on all paths, while current through each path...
There's only one path in a series circuit. If there's any more than one, no matter how many, then it's a parallel circuit. In a parallel circuit, if there are N elements (capacitors, resistors,...
Is this a question? A circuit needs a complete path, a loop. This doesn't necessarily mean it needs wires. Ground, for example can be a path, or the human body.