Anything that can be done on a computer can be sent over the lines. It can be synchronous or asynchronous. An example of an asychronous mode is electronic mail. Items generated on computer which are normally printed and then sent by facsimile can be sent by E-Mail. Computer conferencing is an emerging area for distance education.
Some institutions offer credit programs completely by computer.
Students receive texts and workbooks via mail. Through common files assigned to a class which each student can assess, teachers upload syllabi, lectures, grades and remarks. Students download these files, compose their assignment and remarks off-line, then upload them to the common files. Students and instructors are usually required to log on for a prescribed number of days during the week. Interaction is a large component of the students' grades.