- Domain and codomain
The set of all permitted inputs to a given function is called the domain of the function, while the set of permissible outputs is called the codomain.
A map transforms a m-dimensional input vector into an n-dimensional output vector.
A filter is a boolean function which either accepts or rejects input vectors.
- Composite components
A composite component is a component with attached components (that is, a composite is the root of a tree). Basically, it means that several components can be plugged to process a chain of operations. Maps and Filters are composite components, Builders are not.