Theoretical linguistics refers to the study of language as a structure and system, with particular emphasis on the underlying rules and principles that govern communication. There are a number of synonyms that can be used to describe this field, including formal linguistics, generative linguistics, computational linguistics, and mathematical linguistics. Each of these terms emphasizes a slightly different aspect of the discipline, but they all share a common interest in understanding the nature of language and its relationship to human cognition. Whether through the creation of formal models, the analysis of linguistic data, or the exploration of linguistic universals, theoretical linguistics is a dynamic field that has much to offer for those interested in language and communication.