An increasing amount of national attention is focused on connecting K-12 schools to the Internet, while at the same time, there is some debate on the benefits of using it in the classroom. Most teachers know the Internet is a source of information, but may not know how it works or how to use it. This ERIC Digest provides a framework to explain Internet concepts and terms. The digest describes the following four levels which make up the Internet model: (1) engineering level--the infrastructure that allows information to move from one computer to another; (2) application level--the software that allows users to gather and share information; (3) information service level--the combination of information with hardware and software that allows users to meet their information needs; and (4) use level--the level where users use the information they find on the Internet. New applications and new trends will make the Internet more real-time, more interactive, and more exciting. A constantly changing computer environment will present significant challenges to educators as they attempt to integrate revolutionary technology into an evolutionary teaching process. By understanding the basics of the Internet, educators will be better prepared to face the complexities that will surely follow. (Author/SWC)