A reactive system is a system that changes its actions, outputs and conditions/status in response to surrounding stimuli. The system relies on defined rules setting the relation between the captured data and their representations. Reactive systems are systems whose role is to maintain an ongoing interaction with their environment rather than produce some final value upon termination. Reactive systems locate the design in the realm of circuitry, in assemblages of collectors, servomechanisms and transistors that absorb, process and redistribute matter, force and information.