Single-sex education, also known as single-gender education and gender-isolated education, is the practice of conducting education with male and female students attending separate classes, perhaps in separate buildings or schools. The practice of single-sex schooling was common before the 20th century, particularly in secondary and higher education. Single-sex education is practiced in many parts of the world based on tradition and religion; recently, there has been a surge of interest and the establishment of single-sex schools due to educational research. Single-sex education is most popular in English-speaking countries (regions) such as Singapore, Malaysia, Ireland, the United Kingdom, Hong Kong, South Africa and Australia; also in Chile, Israel, South Korea and in many Muslim majority countries. In the Western world, single-sex education is primarily associated with the private sector, with the public (state) sector being overwhelmingly mixed sex; while in the Muslim world public schools and private schools are sex-segregated. Motivations for single-sex education range from religious ideas of sex segregation to beliefs that the sexes learn and behave differently. As such, they thrive in a single-sex environment. In the 19th century, in Western countries, single-sex girls' finishing schools, and women's colleges offered women a chance of education at a time when they were denied access to mainstream educational institutions. The former was especially common in Switzerland, the latter in the U.S. and the U.K., pioneers in women's education.
In Western Europe before the 19th century, the most common way for girls to access education was at home, through private tutoring, and not at school, due to the strong resistance to women's involvement in schools. This attitude began to change in the 17th and 18th centuries, when girls' schools were established in both Catholic Europe, where they were managed by nuns, as well as in Protestant Europe, where they were managed by governesses, philanthropists, and private entrepreneurs.