Touch is a pervasive human action, which plays an important role in interpersonal relationships, in private as well as in institutional contexts, and which constitutes a fundamental way of sensing the materiality of the world. This introductory chapter offers an overview of the current scientific literature on touch, starting from perspectives that emanate from the neuro-cognitive sciences as well as from social-historical approaches. It then focuses on the contributions of interactional studies, namely within the field of ethnomethodology and conversation analysis, by pinpointing the originality of this perspective in revealing the social, intersubjective, intercorporeal, and interactional dimensions of touch. The chapter elaborates on this interactional conceptual framework by highlighting its methodological consequences and by emphasizing the contribution of video-based multimodal studies of touch. It thus offers a global and explicit synthesis of the conceptual and analytical foundations of this approach, which are then implemented and further elaborated upon in the empirical studies collected in the volume.