This set can be easily identified, has a structured shape and is durable. The people within it act in accordance with the same norms, values and objectives agreed and necessary for the common good of the group and the pursuit of its ends. It can be defined from a series of measurable variables in the economic, labor, educational, etc. level.
For the identification of a social group, a distinctive common identity or belonging is necessary, which can be manifested in a similar culture, and not necessarily in the similarity at the economic level. The members of a social group interact for a common project or forming a discordant subgroup, which finally acquires a controlling character. The potential of a social group is robust both in forming the plot of society and in its denial (opposition party in Parliament, subgroup in the classroom). Formal or informal leaders are the strong point of the plot of interactions in a social group.
When the ascription to a certain social group is strongly determined by economic criteria, the social group of individuals is usually called social class, and is strongly influenced by the kind of family in which the individual is born.
The group is a concept of complicated delimitation. To understand the word "group" in the social sciences, it must be used nuanced by some adjective or appear within a precise and concrete context, because, in practice, it is a term applied to different realities.