PubMed
Short definition
PubMed is a free search engine for biomedical literature, maintained by the United States National Library of Medicine, that mainly provides access to the MEDLINE database.
In plain language
It brings together references and abstracts of articles from thousands of medical, nursing and health science journals, with links to the full text where available. It lets users filter by study type, such as randomised trials or systematic reviews. A search for «virtual reality» and «pain», for example, shows the scale of research on virtual reality for pain. Being indexed in PubMed is not, in itself, a guarantee of quality.