In very simple terms, a web-based learning environment consists of the following components:
A web server is where the contents are stored and virtual learning environment is facilitated. A client workstation is used by a learner to access the learning content and carry out his learning experience. The network establishes a connection between the server and the client through which both the contents can be delivered and student learning data can be exchanged, processed and stored (for later retrieval).
For a more complete description of web-based learning as well as the relevant online resources, please visit Jackson's (2000) excellent webpage at http://www.outreach.utk.edu/weblearning/.