“DOI” is an acronym of Digital Object Identifier, which is used to identify objects electronically by a unique manner in a large central database. This address standardized by the International Organization for Standardization (ISO).
A DOI help user to locate an article for citation, some databases provide DOIs along with permanent links. DOI works like any other permanent link which you will find on article’s information page in any database.
Normally when you search any web page via internet browser, there is a URL in the address bar to view online web content, and easily you are used this URL by copy or paste; but if you want to get a link for an article from the library database, you must require a permanent link.
Different databases call permanent link with different names, such as 'persistent link', 'stable URLs', etc.
You can find or create permanent link for the following platforms: