Observations of the early Universe from Cosmic Microwave Background experiments pin down cosmological parameters characterizing the Universe content and evolution to percent precision. In this talk I will give a brief overview of the current status of CMB observations, focussing on the recent data from the Planck satellite and the ground-based ACT and SPT telescopes. At scales of few arcminute the fluctuations of the primordial CMB become increasingly obscured by extragalactic and secondary signals; I will show how we can take advantage of multi-frequency data to separate out the primary CMB from late-time astrophysical emissions so as not to bias cosmological constraints. I will highlight how we will obtain new information – and better characterization of the cosmological model –  in the next five years with the measurement of CMB polarization.