The current cosmology research has entered a paradigm of precision cosmology on the large scale, where efforts are made primarily to improve our measurements of the cosmological parameters.

On the other hand, the small scale structure of the universe emerges as an active field that encompasses rich phenomenology and is tightly connected to the properties of galaxies, as well as to the nature of dark matter. In this talk, I will introduce a series of works that we have done to study the small scale structure of the universe in the dark matter component, taking advantage of a set of high resolution numerical simulations. I will show how we can identify and model the smallest dark matter structures resolved by simulations in the framework of hierarchical structure formation, and how these results can be confronted with observations to shed light on the nature of dark matter as well as on galaxy formation processes.