Abstract: A digital object identifier (DOI) is a unique alphanumeric string to identify content and provide a persistent link to its location on the Internet. DOI has wide applicability to all forms of intellectual content and can therefore be applied to all forms of related materials, such as article, books, classroom exercises, supporting data, video, electronic files, and so on. It is like a social security number for a document online. It’s a unique and permanent identifier that will take you straight to a document no matter where it’s located on the Internet Information about a digital object may change over time, including where to find it, but its DOI name will not change. DOI names can be used for any form of management of any data, whether commercial or non-commercial.