Creating a progress bar is a crucial aspect of enhancing user experience in command-line interface (CLI) applications, providing real-time feedback on ongoing operations. Unlike a spinner, the progress bar visually indicates the completion percentage, helping users gauge remaining time or tasks. The implementation begins by defining a simple public interface that aligns with user needs, utilizing a constructor for initialization and methods to start, stop, and set progress. Key considerations include using floating-point numbers for precise percentage representation and ensuring the progress bar responds to internal state changes like starting and stopping. The progress is dynamically calculated and visually updated in the terminal, while additional challenges such as error handling, width customization based on terminal size, and responsiveness to window resizing events provide opportunities for further enhancement. This framework serves as a robust foundation for building sophisticated UI components within CLI applications.