Add to ORKGThe purpose of this paper is to provide an informal introduction to the behavioural approach to systems and control. We start with some historical observations. Then we turn to the modelling of dynamical systems and argue that interconnected systems lead to models involving both manifest and latent variables, but which are a far distance from an input/output or a state space description. Subsequently, control questions will be formulated in this setting. As a particular application, we discuss the eigenvalue assignment for linear time-invariant systems. The paper closes with an example of the stabilization of an inverted pendulum.</p