This literature review summarizes research on online teaching and learning. It is organized into four topics: course environment, learners' outcomes, learners' characteristics, and institutional and administrative factors. The authors found little consistency of terminology, discovered some conclusive guidelines, and identified developing lines of inquiry. The conclusions overall suggest that most of the studies reviewed were descriptive and exploratory, that most online students are nontraditional and Anglo American, and that few universities have written policies, guidelines, or technical support for faculty members or students. Asynchronous communication seemed to facilitate in-depth communication (but not more than in traditional classes), students liked to move at their own pace, learning outcomes appeared to be the same as in traditional courses, and students with prior training in computers were more satisfied with online courses. Continued research is needed to inform learner outcomes, learner characteristics, course environment, and institutional factors related to delivery system variables in order to test learning theories and teaching models inherent in course design.Keywords: distance education, Internet courses, online teaching, web-based instruction With the rapid development of technology, online instruction has emerged as an alternative mode of teaching and learning and a substantial supplement to traditional teaching. In the academic year 2000-2001, 90% of public 2-year and 89% of public 4-year institutions offered distance education courses. In the same year, an estimated 2,876,000 individuals were enrolled in college-level, credit-granting distance education courses, with 82% ofthese at the undergraduate level. Of those institutions offering distance education, 43% offered Internet courses using synchronous computer-based instruction, which can also be called online courses (Waits & Lewis, 2003). Synchronous online classes are offered in such a way that all students are online and communicating at the same time, while asynchronous online classes are those that students can log on to and work on even if no one else is logged on at the same time.Web-based education uses the Internet and communication technologies, ranging from the Internet as a research tool to taking online classes. In some instances the Internet is also used to supplement instruction, as in the use of a website to communicate information to students who are in a face-to-face class. Online classes are courses that are delivered completely on the Internet. Hybrid or blended courses are those that combine online components with traditional, face-to-face components. The term distance education is also used to describe any courses that are delivered to students who are not present in the same room. These might be delivered via interactive television, online courses, and courses using videotapes, television, or correspondence. E-learning may be used to describe any learning that is electronically mediated or facilitated by ...