As the deliberations (conducted in the tennis courts at the palace at Versailles) continued, the assemblymen who believed the king should have veto authority began to congregate to the right of the president of the assembly. Those who thought the king should not have veto power congregated on the left.
And that is the origin of the political right and political left.
However, that was a single issue division. Politics rarely is about a single issue, and modern political divisions cannot be represented by any such linear construct. Not even close.
What the left-right analogy has devolved to, at least in the eyes of the left, is a pedestal for moral posturing. Right Wing: bad. Far Right Wing: worse. Anything they want to denigrate automatically is far right wing.
When they call movements with a largely socialist bent -- such as the Neo-Nazis -- far right wing, it has absolutely Sweet Fanny Adams to do with their political disposition and everything to do with the left's desire to associate any movement the general public will find reprehensible with the greater right wing movement.
In short, the terminology long since has lost any political relevance and had become nothing more than a political bludgeon employed most successfully by the Marxists to paint every wackadoodle in the spectrum as a right-wing lunatic.