API versioning is a way for providers to manage breaking changes to their API. Versioning allows for the introduction of new functionality into an API while keeping the existing functionality intact. New functionality added to the API codebase is denoted under a new version number while the existing functionality retains the previous version number. API versioning lets clients continue to use the existing API and update their applications to the newer version when they are ready. By doing this, providers can communicate breaking changes clearly without putting their users at risk.