It is neither a service nor a network; the community of practice is a group of professionals who share knowledge, create common practices and enrich them in areas of common interest. According to Wenger et al. (2002), it was our first social structure, since the caveman, when people gathered around a fire to discuss strategies related to hunting or farming.
We can define it in the following way (Mitchell 2002, Snyder and Wenger 2000, Wenger 1998, Wenger, McDermott, and Snyder 2002):
Sharing of interest, problems, passion for a domain or topic
Sustained mutual relations