The main aim of the current theoretical analysis is to analyze both the classic and current literature on group behavior and teamwork in order to create a consistent image of what working in a team/group actually means. The material is addressed to both academics/researchers (as it synthetizes multiple aspects of the specific literature) and practitioners (which can thus improve the performance of their workplace). Having this dual target audience in mind, the article will cover topics such as: (a) the creation, development and evolutions of teams; (b) how to ensure team effectiveness; and (c) the individual competences (knowledge, skills, abilities and so on) necessary to function in a team. Furthermore, our research also includes brief theoretical analyses of the importance of teamwork in the public sector and the factors which can lead to the creation of more performant public sector teams.