A Digital Object Identifier, or DOI, is a unique alphanumeric string assigned to a digital object, such as a journal article, research paper, or dataset. It provides a permanent link to the object on the internet, making it easier for users to locate and access the content. DOIs are widely used in academic publishing to ensure that citations remain stable over time, even if the object's location changes. When a DOI is assigned, it is registered with a central database, allowing users to resolve the DOI to its current URL. This system enhances the reliability of references in scholarly work, facilitating better research practices and improving the discoverability of academic resources.