semantics
Semantics is the linguistic study of meaning. Semantics, in this respect, contrasts with Syntax in that Syntax focuses on language structure without giving thought to the meaning of the words. Semantics, on the other hand, focuses entirely on the meaning in language, including not only words and sentences, but also gestures, body language, facial expressions, paragraph structure, and punctuation.
Semantics is closely related to philosophy and many philosophers have written topics about linguistic semantics. Semantics as the main focus in linguistic study as opposed to Syntax, was what gave rise to Cognitive Linguistics.
There are many different branches of Semantic study, including Formal Semantics and Lexical Semantics.
Formal Semantics says that expressions are assigned meanings or denotations such as truth-values and relations. These denotations are then compared to the denotations of other expressions. Formal Semantics is a mathematical way of looking at meaning in language and considers language to be logical and mathematical, much like computer programming.
Lexical Semantics looks at the meaning of words using a Morphological perspective. This includes looking at the meanings of not only root words, but also prefixes, affixes, and grammatical markers.