Programming Language Design and Language Semantics - The design of computer programming languages is concerned with the syntax (the words and symbols allowed), the semantics (what they mean) and how easy it is to write programs in the language for particular applications. The appearance and structure of a language's sentences are studied in order to determine which symbol sequences are permitted phrases of the language (syntax), and the assignment of meanings to the sentences of a programming language so that one can explain what the various phrases of a language mean (semantics) and the usability of a language, including the possible areas of application of the language.