“Umwelt” is a German word, translated as “self-world” or sometimes, as “worldview”.
The term was coined by biologist Jakob von Uexküll, and has recently been popularized by the canine behavioral researcher Alexandra Horowitz, who uses it in her book “Inside of a Dog”. She uses the term umwelt to describe the way that dogs perceive the world through their senses, and relate to it using their cognitive abilities.
The umwelt of a dog is different from that of a human, because dogs have different sensory and cognitive abilities; scent, for example, is very important for dogs and allow them to perceive things that humans cannot. Humans, by contrast, can see things in more colors, and recognize complex patterns in the environment in a way that dogs cannot. This means the same object can be endowed with completely different significance, depending on the species perceiving it.