Standard input is a powerful feature in command-line interfaces that allows data to be passed directly into applications, enhancing their functionality and flexibility. By integrating standard input, applications can accept user input dynamically, functioning similarly to file inputs. This capability is particularly useful for chaining commands through the pipe operator, enabling seamless data flow between processes. For instance, leveraging standard input in a word counter application allows for both file-based and direct user inputs, providing versatility in how the application can be used. Implementing this stream not only simplifies user interactions but also strengthens the application's design by allowing it to handle various input methods efficiently. As developers build CLI applications, understanding and utilizing standard input can significantly enhance the user experience and the overall robustness of the application.