Definition
Built-in functions are pre-written code modules that perform common operations within a programming language or software application. These functions are readily available for use without requiring the programmer to define them from scratch, saving time and reducing the potential for errors. They streamline development by providing standardized solutions for tasks like data manipulation, mathematical calculations, or string processing. For instance, a 'print' function in Python allows immediate output of text or variables to the console. Developers sometimes confuse them with user-defined functions, which are custom-written for specific, unique tasks. Understanding built-in functions is crucial for efficient coding and is often tested in domains related to software development and data analysis.