Online forum discussion boards are an important tool for asynchronous learning. The teacher starts the discussion, and students converse among themselves or with the teacher on the forum. It does not require a live interaction, so students are able to post questions and get a reply later, which they can look at when they are available next.
Email allows a student to contact the professor directly while the professor is not physically present and at any time necessary. Emails are sent to the teacher and then the teacher can reply whenever he has time. Students can ask questions, submit class work or discuss the class with the teacher without other students' having access to the email.
Instant messaging is a tool that students can use to interact with each other as well as with the teacher in real time. It allows the students to receive immediate answers to questions. Teachers can use instant messaging to communicate information to students. They can limit IMs to a single student or open a web chat and talk to several students asking the same questions at the same time.
Videos are used in a few ways: as video clips to start discussion, video lectures to convey instruction or video conferencing to talk to students directly. Videos give students a view of the teacher and something to look at as well as convey information without typing. Teachers often use video as a supplement rather than a focus of the class.