The Epoch of Reionization is this era in cosmic history when the neutral Hydrogen in the intergalactic medium turned into its ionized state due to the ionizing fronts produced by the newborn stars, galaxies, black holes, among others. Its progression is directly linked to the UV photons' sources, particularly the first galaxies. This work focuses on the properties of high redshift galaxies, their star formation rate, the feedback of this process with the intergalactic medium, and other observational constraints. Using high-resolution hydrodynamical simulations, we characterize the evolution of these galaxies towards the tail of Reionization and their relation with the dark matter halos, its interaction with the environment, and the self-consistent chemical enrichment. The most remarkable finding of this work is that the budget of ionizing photons to conclude the Reionization era comes from faint galaxies below the resolution of current instruments. However, the upcoming JWST will confirm this assumption by measuring the faint end of the galaxy luminosity function out to z ~ 10 and will extend our understanding of the first stages of the evolution of the cosmic structures.