Often, students may need a particular course for their education but don't live where it's offered. However, thanks to correspondence courses they're able to take courses by mail. Besides traditional college students, correspondence courses focus on full-time employees, military personnel, and other nontraditional students unable to attend in-person classroom lectures.

The correspondence movement evolved in the mid-19th century, fuelled by the need for an educated trade and working class brought on by industrial and urban development, and facilitated by the development of improved printing and postal services. Correspondence courses were first offered in Great Britain, Germany, and the United States but spread rapidly throughout the world.

Originally correspondence courses were largely confined to vocational subjects; now, however, private correspondence schools, industry, government agencies, and universities offer such courses in virtually any field from the elementary school to the postgraduate level. Many of the subjects are not generally given in residence schools: camera repair, horology (clock-making and repair), floristry, locksmithing, gemology, and safety, for example..

Instruction may be wholly by correspondence or by a combination of home study and resident seminars or laboratory work. It may include sound records or tapes, slides, films, videotapes or videodisks, teaching machines, computers, and the use of telephone, radio (including a two-way radio with each student using a transceiver, as in the Australian outback), and television. In the late 20th century the advent of electronic mail (correspondence delivered by means of electronic printing or display devices) is expected to increase the speed of response to student work.

Correspondence courses have several benefits over traditional courses. For example, they don't require traveling time to class and the expense of paying for gas or buying new clothes to wear to a traditional classroom. They also offer a great deal of flexibility for one's schedule. You're able to study at your own pace, going as slow or fast as you're able. If you have either a full- or part-time job, you can take a correspondence course with less interference from work hours. This affords more time spent with family, on hobbies, and on other priorities.

Method of providing education for non resident students, primarily adults, who receive lessons and exercises through the mails or some other device and, upon completion, return them for analysis, criticism, and grading. It is extensively used by business and industry in training programs, by men and women in the armed forces, and by the governments of many nations as part of their educational program. It supplements other forms of education and makes independent study programs readily available.

In India correspondence education has a very long history. After the concept of open universities emerged, it lost some point to them. However, these open Universities are also offering correspondence course to students. But some regular Universities like University of Delhi, Jamia Milia University, and Madurai Kamaraj University are in the top list of correspondence course.