In the current outlook of education, collaborative learning has been introduced as a strategy to build knowledge, in a multimodal culture where information is expressed, produced and distributed through new formats and representational languages. Regarding the latter, the dia-gram has been used as a way to represent and organize information in learning processes, making its comprehension necessary, since there are different interpretations from the theory. That is why, through this study of theoretical design, a systematic review of the literature (SRL) was carried out, which it allowed to get information about the concepts of diagram and its conno-tation in collaborative learning, taking into account the definitions stated about it. The results show that the diagram is a representational instrument and not only a graphic or textual orga-nizer, but also, a semiotic-social mental artifact, a semiotic-social mental artifact that mediates meanings and regulates their construction in subjects' collaborative learning interactions. Finally, the role of the diagram as a potentiator in the development of metacognitive skills is highlighted.