As a result of intense global competition, companies are considering novel approaches to enhance the operational efficiency of their products. In addition, competitive market requirements as well as demands for increased warranties and the severe liability of product failures have forced manufacturers to improve the reliability of their products. Higher field reliability requires knowledge of in-service use and life cycle environmental and operational conditions. Thus, interest has been growing in monitoring the ongoing health of products and systems in order to predict failures and provide warnings in advance of catastrophic failure. This paper provides a basic understanding of prognostics and health monitoring of products and systems and the techniques being developed to enable prognostics for electronic systems.