The Planck satellite dedicated to the observation of the Cosmic Microwave Background (CMB), has observed the microwave sky providing full sky maps at nine frequencies between 30 GHz and 857 GHz with unprecedented precision. Planck observations allowed to perform the most accurate analysis of the different emissions which compose the microwave sky providing descriptions of the phenomena involved which will be the legacy for years to come. I will describe how Planck data allowed to perform an accurate component separation which provides the most precise CMB full sky maps in temperature and polarization together with maps and descriptions of the single foreground components, from the lowest to the highest frequency channels. I will describe also the power spectrum approach which is used in the derivation of the cosmological parameters and how it accounts for foreground residuals and secondary anisotropies. Finally I will conclude with a look to the future of CMB observations and how the Planck legacy will be the starting point for the future experiments.