The term Communities of Practice is relatively new, and yet has assumed an important place in recent discussions of informal learning. In short, it describes interactions and resultant learning when people with common interests associated with their professions interact regularly.

Communities of Practice may develop within an organization, or may involve persons who are from different organizations.

Communities of Practice exemplify a somewhat new learning concept that is useful to training professionals because it involves theories that help create a richer picture of learning. For example, it helps to explain and apply the concept of tacit learning, which is the ability to use and convey knowledge that, while useful, isn’t easily conveyed by those who have it and who, at most, are only vaguely aware of. Tacit knowledge is generally conveyed informally (and unknowingly) by "rubbing off" through informal observation and imitation. Clearly, this kind of knowledge transfer can be extremely valuable, and something to be fostered within an organization.