What is Kant's purpose in writing "What is Enlightenment?" What does this term mean?

Immanuel Kant's purpose in writing "What is Enlightenment?" was to define the term and encourage individuals to use their own reason and understanding, without guidance from another. He was responding to a question posed in a monthly magazine, and his essay has become one of the defining documents of the Enlightenment era.

The term "Enlightenment," according to Kant, refers to man's emergence from his self-imposed immaturity. Immaturity is the inability to use one's understanding without guidance from another. This immaturity is self-imposed when its cause lies not in lack of understanding, but in lack of resolve and courage to use it without guidance from another. Enlightenment is the process of undertaking to think for oneself, to employ and rely on one's own intellectual capacities in determining what to believe and how to act.

Enlightenment philosophers from across the geographical and temporal spectrum have had similar thoughts about the nature of enlightenment, all centered around the idea of becoming aware of and questioning previously accepted beliefs and social structures.