This document defines language and linguistics and outlines the major subfields. It begins by defining language as the innate ability of speakers to form grammatical sentences, according to Chomsky, and as the total set of utterances in a speech community, according to Bloomfield. Linguistics is defined as the scientific study of language structure, including grammar, syntax, and phonetics. The major subfields are then micro-linguistics, focusing on language structure, and macro-linguistics, relating language to society. Micro-linguistics includes phonetics, syntax, and morphology, while macro-linguistics includes language geography, biolinguistics, and psycholinguistics.