In contrast to traditional humanistic approaches to studying language, linguistics focuses not on the ideas that are communicated but rather on the linguistic systems that allow this communication to take place.
What are the atoms of language, and how do they fit together to form utterances? Why do languages vary in the ways they do, and what accounts for the striking similarities among them?
Linguists study these questions from a variety of linguistic perspectives, which include the sounds of language (phonetics and phonology), word-formation processes (morphology), grammar (syntax), and meaning (semantics).
Linguistics defines the levels of structure based on analysis across and within languages.
Linguists also use their analysis of language to understand how and why languages vary and change, how language evolved in humans, how languages are acquired and can become impaired, and how they reflect societies and cultures.
Image source: National Visualization and Analytics Center: Illuminating the Path: The Research and Development Agenda for Visual Analytics p.110. Authors: James J. Thomas and Kristin A. Cook (Ed.); from Wikimedia Commons