This tutorial describes the C Information Abstraction System, a tool which helps fill the needs of C programmers working with large software programs. The system consists of two subsystems: the C Information Abstractor (CIA) and the Information Viewer (INFOVIEW). CIA is a program which abstracts compilable C source code into a set of relations and summaries of software objects. This set is stored in a program database where INFOVIEW can use it to produce vital information necessary for program understanding. The main role of INFOVIEW is to provide a simple user interface to the CIA database; however, it also functions as a programming interface for individuals who wish to use the available information to create their own systems. Written originally on a VAX 11/750 operating 4.3BSD, CIA and INFOVIEW have been ported to UNIX System V and SUN 3.0 systems.