Introduction to Finite Automata and Regular Expression

A finite automaton (FA) is a simple idealized machine used to recognize patterns within input taken from some character set (or alphabet) C. The job of an FA is to accept or reject an input depending on whether the pattern defined by the FA occurs in the input. Regular Languages are the most restricted types of languages and are accepted by finite automata. A language is regular if it can be expressed in terms of regular expression, Finite automata. Finite Automata is characterized into two types Deterministic Finite Automata and Non Deterministic Finite Automata