Reflection is nowadays often used as a learning tool in preschool. In order to learn more about reflection as a tool, more research is needed. The first purpose of my study is to show what reflection is and why it is important for children’s learning. Another purpose is to investigate how educators use reflection in preschools in Sweden. In addition, this study aims to find out which factors affect the quality of reflection. To achieve these aims,  three research questions have been selected: ‘What is the significance of reflection for children and educators and how does it affect the children's learning?’, ‘How do educators use reflection with the children?’ and ‘Which factors have an influence on reflection as a tool?’. The method used in this study is tree observations and nine interviews. These were analyzed to produce the results. The theoretical framework used is Vygotsky's socio-cultural learning theory and the study focuses on two central concepts, namely scaffolding and cultural tools. The results show that children's and educator's reflection is of great importance to children's learning. In addition, they indicate that the teachers work differently to reflect with the children. They use reflection when children gather as a group, with open questions, when doing small group work and with digital tools. The results also show that if the learning environment is inappropriate, reflection cannot be used. An additional result is that a deep reflection is time-consuming and therefore requires a sufficient amount of educators. Finally, the educators own will and understanding play a major role in the effectiveness of reflection as a tool.