Ignorance is a lack of knowledge or understanding. Deliberate ignorance is a culturally-induced phenomenon, the study of which is called agnotology.
The word "ignorant" is an adjective that describes a person in the state of being unaware, or even cognitive dissonance and other cognitive relation, and can describe individuals who are unaware of important information or facts. Ignorance can appear in three different types: factual ignorance (absence of knowledge of some fact), object ignorance (unacquaintance with some object), and technical ignorance (absence of knowledge of how to do something).[1]