What is the need for separating analysis phase into lexical analysis and parsing?

Separating the analysis phase into lexical analysis and parsing helps to break down the process of interpreting the structure of a source code into more manageable steps. Lexical analysis focuses on breaking the input into tokens, which are the smallest meaningful units, while parsing constructs a parse tree or syntax tree to represent the grammatical structure of the code. This separation allows for easier maintenance, testing, and implementation of new features in the compiler or interpreter.