This paper reviews critically the relevance of social interaction and social relations as the core foundation for all human endeavours, making it possible for people to live together in every existing society. This is with a view to give a clear understanding and to demonstrate its centrality in the existence of human societies and in the emergence of the discipline of sociology. The objective of this paper is to create an understanding of social interaction and social relations. The paper employed the symbolic interactionist perspective to review the components and types of social interaction, socialisation and how it has evolved over the years. The study reveals that social interaction and social relations are very important, and form an integral part of human societies and this is why stigmatisation and ostracism are very effective as tools of social control and regulation. The study also reveals that social interaction and social relations form both micro and macro sociological orientations and have evolved over time, and this evolution has been facilitated by advancement in technology and globalisation. The paper concludes that the development of human beings and their societies depends on social interactions and social relations. The study recommends that the turn that social interaction and social relations takes can determine the level of development because if, social interaction is chaotic, it will bring about confusion and conflict and there will be little or no development. But, if social interaction were that of cooperation, more development would be recorded by society.