A code repository, often referred to simply as a repo, is a storage location for software development projects that includes not only the actual code but also all the historical versions and revisions. This enables developers to track changes, revert to previous versions if necessary, and collaborate effectively with others. Repositories are essential for any development process employing version control systems like Git. They facilitate continuous integration and delivery by allowing teams to manage changes in a centralized or distributed manner. Popular platforms hosting code repositories include GitHub, GitLab, and Bitbucket, each offering unique features like branch management, pull requests, and access control mechanisms to enhance collaborative coding practices.