model is spirit and machine is body.
generally speaking, many people cosider software is spirit of machine, but in my opinion, it is not, software is also a part of machine, actully we can think more deeply, the intension of software is that to make machine without knowing electricity's mechanism.
so, about model, it makes me remind mathematic model and 3D model, what is the different of them? however, 3D model only one of mathematic model, in mathematic model, it includes Geometry, Algebra and Analysis. 3D model is geometry part of mathematic model. in generally, 1+1=2, is also a model. a model, is a real-world object's abstract.
we utilize programming to represent model. for designing model, that we have some tools, such as UML. programming is a skill of building something, with a normal person, she/he will very familiar it in an infinite time. but not everybody can well design a model. because of designing a model it will involve many aspect of real-world.
take an example, to design a hotel manage system. if you are good at programming, but you not good at hotel's business. that you will not design a good machine for manage the hotel. so i have a words, modeling is business-orient rather than programming.
that is why i say 'model is spirit and machine is body'.