1 Southern Federal University, 105/42 Bolshaya Sadovaya Ul., Rostov-Na-Donu, 344006, Russia.
2 Concordia University, Boulevard de Maisonneuve West, 1455, H3G 1M8, Montreal, QC, GA-2.126, Canada. eugene.borokhovski@concordia.ca.

In this article, we attempt to integrate and further develop conceptual ideas about functions of small groups and the informal subgroups that arise within them in relation to their respective members, namely, the functions of: (1) creating possibilities for realizing individual goals and meeting individual needs; (2) providing protection from external and intragroup social threats; (3) providing information to members; (4) educating members; (5) providing adaptive capacities to members; and (6) providing control and regulation. First, drawing on a functional analysis, we defined the concept of "function." Next, we touched upon such issues as: the essence of each function; conditions for implementing the functions; the difference between an informal subgroup and a small group in how they implement the functions for their respective members; the effects of implementing the functions; and the related dysfunctions. This versatile account of the functions that small groups and informal subgroups implement in relation to their members allowed us to expand our understanding of these functions and their effects on attitudes, activities and the development of group (subgroup) members, as well as of some aspects of group and subgroup processes and performance. We conclude by presenting both theoretical and practical applications of the analysis of the functions of groups and subgroups and, accordingly, posed some important questions for further research and discussion.