This chapter provides definitions of pain and stress, particularly focusing on the issue that 'stress' as a stand-alone generic term may not be helpful in terms of advancing our understanding of the impact of animal management on animal welfare. For cattle, as for other animals managed by humans, it is necessary to consider the source of 'stress' and to consider the general and specific animal responses to different contexts and events. It outlines the standard methods of assessing pain and stress, then presents a number of new methods that are being used to assess the experiential aspects, explains their theoretical background and how they allow us to gain a better understanding of the experience of pain and stress in cattle than previous methods with respect to the major sources of pain and stress. Finally, the chapter provides a case study describing a situation where these approaches have led to clear recent improvements in practice that are having real benefits for animals under commercial management.