Planck: discovering insight of the Universe

This article is a brief introduction to the observations of the cosmic microwave background radiation, with particular emphasis on the Planck 2015 results on cosmological parameters, gravitational lensing, B-mode polarization with its relation to BICEP experiment, constraining inflation models, constraining dark energy models, and detecting the missing baryons. Finally,a prospective view to the future observational cosmology is presented.