In this module describe what is meant by dementia, different types and the prevalence of dementia. We examine the changes that occur in the brain in Alzheimer's disease and vascular dementia. The bulk of the module focuses on how dementia-related damage to particular regions of the brain affects brain function. We look at how this relates to a person's cognitive difficulties and responses, in the residential care setting. In the last part of the module, we consider how symptoms of dementia and responsive behaviours may manifest in a person in care settings. This is module 1 in the 3-part module series: The view from here: Skills in aged and community dementia care