A concept is a set of requirements to a type, which are necessary and sufficient for the type to model a particular behavior or a set of behaviors. Some concepts are specific to a particular algorithm (e.g. algorithm body), while other ones are common to several algorithms (e.g. range concept).
All TBB algorithms make use of different classes implementing various concepts. Implementation classes are supplied by the user as type arguments of template parameters and/or as objects passed as function call arguments. The library provides predefined implementations of some concepts (e.g. several kinds of ranges), while other ones must always be implemented by the user.
TBB defines a set of minimal requirements each concept must conform to. Here is the list of different concepts hyperlinked to the corresponding requirements specifications: