Distance learning was once only possible by corresponding through the mail. In the late 1970s and 1980s, higher education institutions in the U.S. and Europe began delivering instructional content to distance learners over cable and satellite TV. From the mid-1990s onwards, the Internet rapidly became the most common method of delivering distance education.
Online education is "synchronous" if the teacher and student have some direct, simultaneous contact. For instance, a teacher might meet with students in a chat forum for a discussion. Another example of synchronous distance learning is a teacher delivering a lecture at a scheduled time while students watch it simultaneously via a webcam.
Distance learning also allows for "asynchronous" learning, where instructor and learner do not meet in time or space. For instance, a student may go to a website to read or watch the week's lectures at any point during the week. Students may use email to submit assignments to the teacher or ask questions. Asynchronous learning opens up enormous possibilities by divorcing education from the constraints of time as well as place.
Online education makes more subjects of study available to more students. According to the U.S. Department of Education, in 2002, 78 percent of family households had a connection to the Internet. Online classes can reach individuals who traditionally found access to learning difficult, such as people with full-time jobs, women with family responsibilities, people in remote locations and students with medical or developmental challenges.
Online education originated at the college level, but today many professional certifications are available online. U.S. Department of Education surveys show that online classes are popular with adult learners of all races, with all levels of prior education. Online career and continuing education reaches learners from trade and service careers as from professional careers.
During the academic year 2006-2007, the U.S. Department of Education found that 65 percent of two-year and four-year post-secondary institutions offered college-level online learning for credit. Community colleges make the greatest use of online learning to cut costs and reach a wide audience of learners. A full 97 percent of two-year public institutions offer credit-granting online learning.
Today online education is making inroads into kindergarten through 12th grade. During the academic year 2002-2003, independent researchers at Eduventures found that 300,000 American high school students took classes online. Most of these students used online classes to fill gaps in the courses available at their public high schools. Public school systems increasingly use online learning. For instance, West Virginia schools provide students with online foreign language instruction when they cannot locate or afford new Spanish teachers, say Edutopia researchers.