formal language
Formal languages generate the syntactic construction and classification of words that can be formed over a finite alphabet. The theory of formal languages forms the basis for many other areas of theoretical computer science, in particular information processing, compiler construction, and model building. Formal languages are generated with the help of formal grammar. With respect to the formal languages a language hierarchy can be defined. This summarizes languages in each case of same characteristic and expression strength to language classes within the so-called Chomsky hierarchy.
A formal language is always a set of character strings. The attribute "formal" refers to the system-related aspect, since in theoretical and technical systems a smaller number of words is usually sufficient to exchange information. Therefore, an orientation to natural languages is also not meaningful.
A language is always inseparable from its grammar, i.e. the grammatical rules of a language determine its syntax. Thus, syntax, as the study of sentence structure, has a central role in a formal language, whereas semantics, and thus the meaning of sentences, is irrelevant.
Automata interpret and process the expressions formed by formal languages. Each formal language can be assigned to a defined language class. The automata thereby form the model of a computing machine, while the languages provide the model for the formation of the inputs to be processed by the computing machine.
Definition: Alphabet, Character, Word and Formal Language
Formal languages are not only important for information exchange, but also for basic research. For example, methods for speech and character recognition are derived from natural languages.