Good question Phil. In the OP, I mean.
Far right / far left ; they are just labels, and shorthand to describe people who have extreme views at either end of the politics spectrum. Usually about social issues, in my experience, like sexuality, religion, race, freedom of speech etc.
In power, there is very little difference between the two in terms of what they do. And their attitudes are borne out of a mixture of upbringing, ignorance, low self-esteem and innate social conservatism about everyone and everything that doesn't fit the prism that they view life through. In my opinion.