What is parsing

Parsing is the procedure of analyzing a text, made of a sequence of tokens, to define its grammatical structure regarding to a given formal grammar. Parsing is as well known as syntactic analysis and parser is employed for analyzing a text. The task of the parser is necessarily to determine if and how the input can be derived from the start symbol of the grammar. The input is a valid input along with respect to a given formal grammar whether it can be derived from the start symbol of the grammar.