The document compares communities of practice to other types of groups. Communities of practice are formed by members who share a passion or expertise in a subject. They are held together by ongoing interest from members and last as long as there is interest in maintaining the group. In contrast, formal work groups are formed to deliver a product or service and include anyone reporting to the same manager. Project teams are assembled to accomplish specific tasks and include employees assigned by senior managers until the project's completion. Informal networks are for collecting and sharing business information among friends and acquaintances as long as there is mutual benefit from connecting.