Automata Theory is a branch of computer science that studies abstract machines, known as automata, and the problems they can solve. It provides a framework for understanding how machines process information and make decisions based on input. This theory is fundamental in designing algorithms and programming languages, as it helps in analyzing the capabilities and limitations of computational systems. The theory includes various types of automata, such as finite automata, pushdown automata, and Turing machines. Each type has different levels of complexity and power, allowing researchers to classify problems based on their solvability. Automata Theory also intersects with formal languages, which describe the syntax and structure of programming languages.