Code documentation is essential for maintaining readability, developer collaboration, and extending the functionality of software development projects. By using well-documented code, developers can better understand and modify existing code, improve teamwork among development teams, reduce mistakes and problems, serve as a reference manual for aspiring programmers, and provide transparency to stakeholders. Poorly documented code, on the other hand, can lead to reduced code understandability, increased time and effort for understanding and debugging, knowledge dependency on specific individuals, difficulty in collaboration and teamwork, increased risk of errors and bugs, impacted maintenance and upgrades, difficulty in onboarding new team members, lower code reusability, increased technical debt, and lack of transparency for stakeholders. To improve the quality and effectiveness of code documentation, developers should follow best practices such as writing clear and easy-to-understand language, describing complex or non-obvious code, following a consistent documentation style, keeping current documentation up to date, being forthright about limitations or errors in the code, planning and organizing documentation, offering references and links, including visuals, encouraging feedback and participation, and using proper documentation tools such as Javadoc, Sphinx, Doxygen, Markdown, and CodiumAI.