The relationship between a hypothesis and a model and a theory
There is not usually any difference between a hypothesis and a model in science. A model is basically our hypothesis of the nature of a phenomenon. (However, not every hypothesis need be a model; some hypotheses are not related to the nature of things, but only to the existence or nonexistence of a certain phenomenon.) In technical fields, models are intended so that study of their behaviour in cases where this is advantageous or even necessary can replace study of the behaviour of the actual, modelled object. Models are created in science so that we can test their validity and thus reject the relevant hypothesis. A theory is actually a more complicated hypothesis, to be more exact, it is a system of several or a great many interconnected hypotheses. The usual concept of lay persons that a hypothesis is an insufficiently verified theory certainly does not hold true.