Deschooling is the mental process a person goes through after being removed from a formal schooling environment. It usually refers to children who have been removed from school for the purpose of unschooling, but technically applies any person leaving school, either by dropping out or graduating.
The term is sometimes used to mean the same thing as unschooling. Some parents who wish to unschool their children consider it necessary to first deschool themselves if they wish to avoid creating an environment of "school at home" in favor of fostering a less restrictive learning environment where the child largely directs his or her own learning.
Some people extend the concept of deschooling beyond the individual and call for an end to schools in general. This is based on the belief that people learn better by themselves, outside of an institutional environment.
Deschooling Society is a famous book by Ivan Illich.