Define formal language grammar?

A formal language grammar is a set of formation rules which describe that strings made by the alphabet of a formal language are syntactically valid, inside the language. A grammar just addresses the location as well as manipulation of the strings of the language. This does not explain anything else about a language, as its semantics.

As suggested by Noam Chomsky, a grammar G contains the following elements:

• A finite set N of non-terminal symbols.
• A finite set Σ of terminal symbols which is disjoint from N.
• A finite set P of production rules, all rules of the form

Here * is the Kleene star operator and signifies set union. It is, each production rule maps by one string of symbols to the other, here the first string consists of at least one non terminal symbol.

• An illustrious non terminal symbol from set N which is the start symbol.