Explore the fundamentals of finite automata and regular languages in this comprehensive lecture from CMU's "Great Ideas in Theoretical Computer Science" course. Delve into deterministic finite automata (DFAs), their anatomy, and computational processes. Learn about regular languages, string notation, and problem representation in theoretical computer science. Practice DFA construction and discover techniques for proving whether a language is regular or not. Gain insights into the Union Theorem and its applications in automata theory.