The cosmic microwave background contains a wealth of information about cosmology as well as high energy physics. It tells us about the composition and geometry of the universe, the properties of neutrinos, dark matter, and even the conditions in our universe long before the cosmic microwave background was emitted. After a brief review of what we may hope to learn from studies of the cosmic microwave background about the early universe, I will review measurements of the angular power spectrum of temperature perturbations from the first 15.5 months of Planck data by the Planck collaboration and by Renee Hlozek, David Spergel and myself. I will also discuss the implications for the early universe of the recently released Planck full mission data as well as the joint analysis between BICEP/KeckArray and Planck.