A simulator is a collection of hardware and software systems which are used to mimic the behaviour of some entity or phenomenon. Typically, the entity or phenomenon being simulated is from the domain of the tangible -- ranging from the operation of integrated circuits to behaviour of a light aircraft during wind sheer. Simulators may also be used to analyze and verify theoretical models which may be too difficult to grasp from a purely conceptual level. Such phenomenon range from examination of black holes to the study of highly abstract models of computation. As such, simulators provide a crucial role in both industry and academia.
Despite the increasing recognition of simulators as a viable and necessary research tool, one must constantly be aware of the potential problems which simulators may introduce. Many of the problems are related to the computational limitations of existing hardware platforms but are quickly being overcome as more powerful platforms are introduced. Other problems, unfortunately, are inherent within simulators and are related to the complexity associated with the systems being simulated. This section highlights some of the major advantages and disadvantages posed by modern day simulators.