In this presentation, the general ideas of the theory of practice architectures are introduced in the context of professional development of teachers. Despite the fact mentoring has become a mantra in teacher induction, there seems to be various understandings of (1.) the activities and actions, (2.) the concepts, and (3.) the relationships between people involved in induction. In the various educational contexts, mentoring can be understood as a special kind of “practice” which is formed through particular “pratice architectures”. A “practice” is a distinctive human social project; a coherent and complex form of socially established cooperative human activity in which characteristic arrangements of (1.) actions and activities are comprehensible (“doings”; in physical space-time) (2.) in terms of arrangements of relevant ideas in characteristic discourses (“sayings”; in semantic space), and (3.) when the people and objects involved are distributed in characteristic arrangements of relationships (“relatings”; in social space). These sayings, doings and relatings ‘hang together’ (‘zusammenhang’) and constitute “practice architectures” and “metapractices”. “Mentoring”, for example, may be understood as a practice within a more comprehensive metapractice of “education”.