distance learning , also called distance education, e-learning , and online learning , form of education in which the main elements include physical separation of teachers and students during instruction and the use of various technologies to facilitate student-teacher and student-student communication. Distance learning traditionally has focused on nontraditional students, such as full-time workers, military personnel, and nonresidents or individuals in remote regions who are unable to attend classroom lectures. However, distance learning has become an established part of the educational world, with trends pointing to ongoing growth. In U.S. higher education alone, more than 5.6 million university students were enrolled in at least one online course in the autumn of 2009, up from 1.6 million in 2002.
An increasing number of universities provide distance learning opportunities. A pioneer in the field is the University of Phoenix , which was founded in Arizona in 1976 and by the first decade of the 21st century had become the largest private school in the world, with more than 400,000 enrolled students. It was one of the earliest adopters of distance learning technology, although many of its students spend some time in classrooms on one of its dozens of campuses in the United States , Canada, and Puerto Rico . A precise figure for the international enrollment in distance learning is unavailable, but the enrollment at two of the largest public universities that heavily utilize distance learning methods gives some indication: in the early 21st century the Indira Gandhi National Open University, headquartered in New Delhi , had an enrollment in excess of 1.5 million students, and the China Central Radio and TV University, headquartered in Beijing , had more than 500,000 students.
Students and institutions embrace distance learning with good reason. Universities benefit by adding students without having to construct classrooms and housing, and students reap the advantages of being able to work where and when they choose. Public-school systems offer specialty courses such as small-enrollment languages and Advanced Placement classes without having to set up multiple classrooms. In addition, homeschooled students gain access to centralized instruction.