Supernovae are among the strongest explosions in the universe and play an important role in many aspects of astronomy: from the production of heavy elements to their use as standard candles to probe the early universe. But they also probe many aspects of physics: from the behavior of matter at high densities to the effects of high gravitational fields. I will review the basic mechanism behind core-collapse supernovae and highlight the latest advances in our understanding of these cosmic explosions. In particular, I will highlight our recent 3-dimensional results and emphasize the evidence and the explanations for asymmetries in these explosions.