This position on reality claims that knowledge and value are not absolute but are relative to a person's nature and situation. Post-Einstein physics is emblematic of this stance, though the cultural relativism was also greatly influenced by anthropologists and reinforced by the increasing prevalence of travel, supercharged by the increasing rate of social change.
Because relativism has developed in a time of declining influence for religion, it is to science that it addresses its challenge. The relativist argument against the objectivist position is frequently based on the existence of constraints on our ability to directly perceive the world. There are neurological constraints, such as our ability to see and hear only within certain band-widths of the electro-magnetic spectrum; social constraints, such as the influence of a language on a speaker's experience together with the recognition that different cultures make sense of some things in very different ways; and individual constraints, such as the different preferences that derive from our very different personal histories. All of this leads each of us to experience the same event in quite different ways.
Characteristic of Relative Reality is that the ground of reality is in the knower. This position is well represented by the familiar story of the blind men and the elephant. Because one man is feeling the elephant's trunk, another its leg, another its flank, and the last one its tail, each has a very different experience and gives a very different description of the elephant.
At present we live in a mixed state of reality, part absolute, part relative. Assailing the absolutes has been something of a sport since the Sixties. This led, in the social world, to the "crisis of legitimization." Since authority had justified itself on the grounds of one or another absolute, its basis became less convincing. And those who held authority seemed less confident in its exercise. Moral relativism undermined the basis for evaluating behavior and even the certainties of Law.
Moving out of Absolute Reality into Relative Reality can feel as if all certainty is evaporating in a moral meltdown, and spur you to reach for the door to the past. But Relative Reality can feel like freedom if all that certainty had been weighing you down. The problem with living in a relative reality is that it can be alienating. I'm alone in my reality; you're alone in yours. We may have consensus about something, but even "consensual reality" is itself not real. Moreover, we have no way to contact the real reality; it is forever beyond our grasp. This can diminish our experience. It isn't real and we're alone with it.