A recursive descent parser is a computer program designed to take input as a language, such as a list of tokens generated by the lexer, interactive online commands, markup tags, sequential source program instructions, or some other form of defined interface, and convert it into an abstract data structure that can be handled by other programs, such as other parts of a compiler. Usually this conversion involves breaking the input up into usable parts that is done using recursion. It is basically a translator and is usually part of a compiler. This particular type of parser, a recursive descent parser, uses recursive procedures to model the parse tree that is to be constructed that is it is an algorithm that calls itself within some part of executing its own task. It can be as simple as taking a string of input and cutting off...