The structures in our universe have grown from tiny primordial matter fluctuations. The theory of inflation tells us that these primordial seeds were quantum fluctuations generated during a period of exponential expansion of the very early universe. The basic cosmological parameters (expansion rate of the universe, baryon density of the universe, matter density of the universe, geometry of the universe, etc) and the power spectrum of the primordial matter fluctuations together provide a fundamental picture of our universe.

I will discuss three complimentary probes of our universe: (1) the anisotropy of the cosmic microwave background radiation; (2) the large scale distribution of galaxies; (3) the brightness of cosmological standard candles (type Ia supernovae). I will show how observational data can allow the accurate measurement of important cosmological parameters, a measurement of the primordial power spectrum independent of inflationary models, and strong constraints on the nature of the dark energy in the universe.