DOI
Short definition
A DOI is a unique, permanent digital identifier assigned to a scientific article, book or dataset, providing a stable link to it even if its web address changes.
In plain language
It takes the form of a prefix and a suffix, such as 10.1136/bmj.n71, and resolves through https://doi.org/. It is standardised by ISO 26324 and managed by the DOI Foundation. Citing a study's DOI allows anyone to find the exact source, which is useful for checking a claim about the evidence for an intervention.