Q. What is a DOI?

A DOI (digital object identifier) is an alphanumeric code assigned to a journal article. It is intended to make articles easier to locate on the internet. A DOI provides a persistent, permanent link to your article's location on the internet. 

How do I recognize it?

They usually start with a 10 and are displayed as an alphanumeric string of digits or a web page URL. Examples: 

• 10.1016/j.jpsychires.2017.11.014
• doi:10.1080/02626667.2018.1560449
• https://doi.org/10.1111/hex.12487

Do all articles have a DOI?

No, but most publishers do assign DOIs to articles. Some older articles may not have DOIs. 

Are articles with a DOI peer-reviewed?

DOIs are not related to the peer-review status of an article. Both peer-reviewed and non-peer-reviewed articles can have DOIs.

Does my article have a DOI?

You can look up an article's DOI using CrossRef's DOI tool.

Related:

How do I search for an article by DOI?