Observational cosmology became a science on the basis of two observations: the expansion of the universe and the presence of the Cosmic Microwave Background Radiation. Models of its evolution are based on Einstein’s theory of General Relativity. Modern models include the presence and properties of dark matter and also of dark energy, within the standard framework known as ΛCDM. These models are used to predict the large scale evolution of structures in the universe and also the small scale structures, which means galaxies and their components. The models predict how galaxies should have formed and evolved from when conditions first permitted their formation, to the present time. In turn this means that galaxies can, and must be used to test the predictions of the models. This chapter surveys this whole scenario, starting with the successes of the models in predicting large scale structures: superclusters and voids, but including the difficulties faced when predicting the detailed properties of galaxies, and their evolution. It combines detailed observation and interpretation of the history of local galaxies with cosmological interpretation (“galactic archaeology”) with observations increasingly closer to the epoch of the first galaxies, by the Hubble Space Telescope, and particularly by the James Webb Space Telescope. As well as the formation of the galaxies, we need to know the processes which cause them to grow, or to stop growing, as time progresses. The former include accretion of small galaxies and large gas clouds by large galaxies. The latter include feedback from strong star forming regions, and central supermassive black holes. The chapter ends with measurements on some of the earliest galaxies to form, recently detected with the JWST, only 300 million years after the Big Bang, in a universe which is almost 13,800 million years old. And the scene is set for a new era of cosmic discovery in the field of galaxies.