Ignorance is a lack of  knowledge. The word ignorant is an adjective describing a person in the state of being  unaware, and can be used to describe individuals who deliberately ignore or disregard important information or facts or individuals who are not aware of that important information or facts. Ignorance can come in three different types: factual ignorance (absence of knowledge of some fact), objectual ignorance (unacquaintance with some actual object), and technical ignorance (absence of knowledge of how to do something that could actually be done). (Nottelmann) [1]

Reasons for ignorance

People do not experience instant gratification and therefore they do not invest time and effort in learning and developing. Eradicating ignorance completely from an individual’s life is an impossible task but reducing the gap can truly benefit the individual long term (Caplan). [2]

Also, making the decision to remain ignorant by committing to an ideology despite scientific proof is a dangerous mindset that can inhibit an individual from discovering the truth and therefore developing as an individual. (McIntyre) [3]

Ignorance can stifle learning, especially if the ignorant person believes that he or she is not ignorant. A person who falsely believes he or she is knowledgeable will not seek out clarification of his or her beliefs, but rather rely on his or her ignorant position. He or she may also reject valid but contrary information, neither realizing its importance nor understanding it. This concept is elucidated in Justin Kruger's and  David Dunning's work, "Unskilled and Unaware of It: How Difficulties in Recognizing One's Own Incompetence Lead to Inflated Self-Assessments," otherwise known as the  Dunning–Kruger effect.

Another reason why people are not able to obtain knowledge is the inaccessibility to education. In some parts of the world, educational infrastructures are scarce and therefore people are not able to seek knowledge. The phenomenon can be observed widely in underdeveloped countries where many children either cannot afford to go to school or live too far from a school. On the other hand, in developed countries most children have access to a K12 education but once they graduate high school they encounter obstacles to pursue a higher education due to high costs. This lack of education can contribute to individuals not being able to practice critical thinking and seek knowledge for themselves. 

Other Languages
العربية: جهل
български: Невежество
català: Ignorància
čeština: Nevědomost
Deutsch: Ignoranz
eesti: Teadmatus
español: Ignorancia
فارسی: نادانی
français: Ignorance
galego: Ignorancia
한국어: 모름
Հայերեն: Տգիտություն
हिन्दी: अनभिज्ञता
Bahasa Indonesia: Kebodohan
interlingua: Ignorantia
italiano: Ignoranza
עברית: בערות
ಕನ್ನಡ: ಅಜ್ಞಾನ
ქართული: უმეცრება
қазақша: Надандық
Latina: Ignorantia
مصرى: جهل
Nederlands: Onwetendheid
日本語: 無知
Patois: Ignarans
português: Ignorância
română: Ignoranță
русский: Невежество
sicilianu: Gnuranza
Soomaaliga: Jahli
ייִדיש: איגנאראנץ
中文: 无知