Maximizing the interaction between pupils with and without special needs is generally considered an important aspect of inclusion. However, it is frequently questioned whether pupils with special educational needs (SEN) in regular classrooms have interactions and friendships with their peers. In order to be able to evaluate these relationships, it is necessary to clarify concepts such as social participation, social integration and social inclusion. At the moment there is much ambiguity regarding these concepts. This article aims to elucidate on these concepts and reveal its characteristic themes. An analysis of literature was carried out to identify these concepts. In the final analysis, 62 articles were included. This analysis showed that the concept social integration and the related concepts of social inclusion and social participation are often described inaccurately, with only a few researchers providing explicit definitions or descriptions. In the majority of articles, implicit descriptions can be derived from instruments used to measure social integration, social inclusion or social participation: it is apparent there is much overlap among the use of concepts by researchers. Based on the analysis of the 62 articles, it can be concluded that the concepts social integration, social inclusion and social participation are used as synonyms. In our opinion, social participation is the most suitable concept. The analysis of literature reveals four key themes central to all three concepts: friendships/relationships, interactions/contacts, perception of the pupil with SEN and acceptance by classmates. (Contains 4 tables and 1 figure.)