This paper is composed of two sections. The first provides a conceptual framework for expressing the attributes of what constitutes dependable and reliable computing: a) the impairments to dependability (faults, errors, and failures), 6) the means for dependability (fault avoidance, tolerance, removal, and forecasting), and c) the measures of dependability (reliability, availability, safety). The second section focuses on one of the most challenging pro& /ems for dependable computing: coping with design faults.