Patents can be distinguished (in some countries such as Italy) in two categories:
The first ones are the patents for protection of an inventive concept, i.e. a new and original solution to a technical problem, whereas the latter identify a new form of an industrial product that gives to the product itself a particularly effectiveness or comfort of application or use.
Inventions, as we have said, are solutions of a technical problem and capable of industrial application. Therefore an invention can be a product and/or a method and/or a use. The utility model proposes a solution to a technical problem too, which is however specific: to give particular efficacy or comfort of application or use by acting on the shape of machines or parts thereof, of instruments, of tools and tool objects in general.
Sometimes to choose between the two categories is not easy, which is why the law permits when necessary to file both.
A big difference is duration, for both non-renewable: the invention patent lasts 20 years from the filing date, the utility model only 10.