A Regular Language is a type of formal language that can be expressed using a finite state machine or a regular expression. These languages are defined by specific rules and can be recognized by simple computational models. Regular languages are important in computer science, particularly in the fields of automata theory and compiler design, as they help in the processing and understanding of strings of symbols. Regular languages can be described using operations such as union, concatenation, and Kleene star. They are limited in their expressive power compared to more complex languages, like Context-Free Languages or Context-Sensitive Languages. However, their simplicity makes them useful for tasks like lexical analysis in programming languages and pattern matching in text processing.