If you reached this module from a web search engine or some other link you probably have no idea where you are. This module is part of on online Unix system administration Education Certification (EdCert) course, written by the Unix Workstation Support Group at Indiana University.
The buttons are for navigation within the EdCert course. The course material is available anyone on the Web. If you are interested in looking through the material the "contents" button will take you to course table of contents. The "Introduction" contains information on how the course works.
Happy browsing!