A research participant is recruited to take part in a study. You might fill out surveys, receive a treatment intervention, take part in a focus group, or be interviewed as part of data collection to answer a research question. Your experiences are the subject of the research.
A public contributor is a person with lived experience of a health condition or who is caring closely for a family member with the health condition. You help shape, guide, and advise on the research itself. You bring your experience and insights to suggest topics, help design the study, make materials clearer, reach the right communities, or help interpret what the findings actually mean – making you a collaborator, not just a source of data.