Much of the debate in this field has focused on analyzing the nature of knowledge and how it relates to similar notions such as truth, belief, and justification. It also deals with the means of production of knowledge, as well as skepticism about different knowledge claims. In other words, epistemology primarily addresses the following questions: "What is knowledge?", "How is knowledge acquired?", and "What do people know?".
"Naïve realism claims that the world is pretty much as common sense would have it. All objects are composed of matter, they occupy space, and have properties such as size, shape, texture, smell, taste and colour. These properties are usually perceived correctly. So, when we look at and touch things we see and feel those things directly, and so perceive them as they really are. Objects continue to obey the laws of physics and retain all their properties whether or not there is anyone present to observe them doing so."
In contrast, indirect or representative realism claims that we are directly aware only of internal representations of the external world, as objects are hidden behind a "veil of perception". Idealism, on the other hand, asserts that no world exists apart from mind-dependent ideas.