Python 2 and Python 3 differ significantly, with Python 3 offering improved features, syntax, and performance. Python 2, though historically popular, lacks ongoing support and updates, making it less secure and less efficient. Python 3 introduces advanced features like better Unicode handling, enhanced standard libraries, and improved syntax. With Python 2's official end-of-life, migrating to Python 3 is crucial for accessing modern functionalities, ensuring security, and maintaining compatibility with the latest libraries and tools. Transitioning now maximizes long-term benefits and aligns with current industry standards, ensuring your projects remain robust and up-to-date.