Card sorting is a UX research technique in which users organize topics into groups. Use it to create an Information Architecture that suits your users' expectations. In cart sorting, participants group individual labels written on notecards according to criteria that make sense to them. Card sorting is a highly useful technique in information architecture; it is used to understand how users think about your content. It can help you organize content so that it suits your users’ mental models, rather than the point of view of your company.