This chapter seeks to provide a reference resource on traceability fundamentals. It defines the essential traceability terminology of trace, trace artifact, trace link, traceability and tracing, and is supplemented by an extensive glossary that has been developed and endorsed by members of the traceability community. This chapter also offers a model of a generic traceability process and describes the essential activities involved in the life cycle of a trace. This model has been used as a frame of reference for articulating the grand challenge of traceability, as reported in the chapter by Gotel et al. of this book. The chapter also describes the basic types of traceability and explains a number of key associated concepts.