In qualitative dynamics (or topology), all possible states that a system can occupy. In complex, dynamical systems, only a small proportion of such states are found, and the system is said to occupy a small state or phase space. The temporal behaviour of a system is seen as succession of states in the system‚was state space that follow trajectories or orbits. It can also refer to the number of all possible initial conditions for such systems. The dimension of the state space is then the number of initial conditions required to uniquely specify a trajectory through it. The set of all initial conditions that go to a given attractor in a state space is called the attractor‚was basin and boundaries such basins are referred to as separatrices
. See Attractor, Behavioral state concept, Catastrophe theory, Complexity, Open system