The goal of this talk is to state Bernstein's theorem, which gives a decomposition of the category of smooth representations of a p-adic group, as wel as discuss recent work related to understanding the structure of Bernstein blocks. Time permitting, I will also talk a little bit about the proof of Bernstein's theorem, and discuss Langlands' classifiction theorem. I hope this talk will be useful to anyone considering attending the 2025 Arizona Winter school (which is on representations of p-adic groups) and will not assume prior experience with representations of p-adic groups.