What is a DOI?
Answer
A Digital Object Identifier (DOI) is a unique identifier for a journal article. Like a person's social security number uniquely identifies one and only one person, a DOI uniquely identifies one and only one journal article. The advantage of searching for a journal article using its DOI is that you can rest assured that you are getting the right version of a journal article. Sometimes, there can be different versions of the same article, so using a DOI ensures that you get the right version. Every journal article has a different DOI. However, some journal articles do not have a DOI at all.
For more information on DOIs go to the DOI System FAQ Webpage.