Check out Part 1 here! Useful Things to Know About Parsers Grammar
A grammar is a formal description of a language that can be used to recognize its structure.
In simple terms, a grammar is a list of rules that define how each construct can be composed. For example, a rule for an “if” statement could specify that it must start with the “if” keyword, followed by a left parenthesis, an expression, a right parenthesis, and a statement.