Linguistics is the scientific study of language. It deals with all these questions and many more. Linguistics can be divided into two broad areas. One is the analytical and systematic study of speech sounds, words, sentences and meaning. The other is the study of the psychological, social and cultural aspects of language.
People study linguistics for many reasons.
You may be fascinated by the beauty and complexity of languages. Or perhaps you are interested in what makes us human, for language is probably the most distinctive human trait. Maybe you are learning or teaching a language, and want to do it better. Or you want to increase your understanding of culture or the social world. Because language is all-pervasive, linguistics has many practical applications.