If you're around testers or reading about testing it won't be long before someone mentions models. (Probably after context but some time before tacit knowledge .) As a new tester in particular, you may find yourself asking what they are exactly, these models. It can be daunting when, having asked to see someone else's model, you are shown a complex flowchart, or a state diagram, or a stack of UML, a multi-coloured mindmap, or a barrage of blocked-out architectural components linked by complex arrangements of arrows with various degrees of dottedness. But stay strong, my friend, because - while those things and many others can be models and can be useful - models are really just a way of describing a system, typically to aid understanding and often to permit predictions about how the system will behave under given conditions. What's more, the "system" need not be the entirety of whatever you're looking at nor all of the attributes of it. It's p...