Random stream (or stream) is an abstract source of pseudo- and quasi-random sequences of uniform distribution. You can operate with stream state descriptors only. A stream state descriptor, which holds state descriptive information for a particular BRNG, is a necessary parameter in each routine of a distribution generator. Only the distribution generator routines operate with random streams directly. See VS Notes for details.
Random streams associated with abstract basic random number generator are called the abstract random streams. See VS Notes for detailed description of abstract streams and their use.