Semantics, the study of meaning. Is part of the linguistics focussed on sense and meaning of language or symbols of language. It is the study of interpretation of signs or symbols as used by agents or groups within particular circumstances and contexts. Semantics asks, how sense and meaning of complex concepts can be derived from simple concepts based on the rules of syntax. The semantics of a message depends on its context and pragmatics.
Syntax, as in grammatics denotes the study of the principles and processes by which sentences are constructed in particular languages.
In formal Languages, syntax is just a set of rules, by which well formed expressions can be created from a fundamental set of symbols, or alphabet. In computer science, syntax defines the normative structure of data.
Context denotes the surrounding in an expression. Its relationship with surrounding expressions and further related elements.
Contexts denotes all elements of any sort of communication that define the interpretation of the communicated content, general, personal or social content.
Pragmatics reflects the intention by which the language is used to communicate a message. In linguistics pragmatics denotes the study of applying language in different situations. It also denotes the intended purpose of the speaker. Pragmatics studies the ways in which context contributes to meaning.
Experience considers all information that you have learned and put in context with the world you are living in.