Open Educational Resources and open access refers to the practice of making peer-reviewed scholarly research and literature freely available online to anyone interested in reading it. Open access resources are digital publications, including individual scholarly journals, books, and repositories of scholarly works, that are freely accessible on the World Wide Web. Open access has two different versions - gratis and libre.
Gratis open access is simply making research available for others to read without having to pay for it. However, it does not grant the user the right to make copies, distribute, or modify the work in any way beyond fair use.
Libre open access is gratis, meaning the research is available free of charge, but it goes further by granting users additional rights, usually via a Creative Commons license, so that people are free to reuse and remix the research. There are varying degrees of what may be considered Libre open access.
PubMed is a free resource supporting the search and retrieval of biomedical and life sciences literature with the aim of improving health–both globally and personally.
The PubMed database contains more than 32 million citations and abstracts of biomedical literature. It does not include full text journal articles; however, links to the full text are often present when available from other sources, such as the publisher's website or PubMed Central (PMC).
PubChem is the world's largest collection of freely accessible chemical information. Search chemicals by name, molecular formula, structure, and other identifiers. Find chemical and physical properties, biological activities, safety and toxicity information, patents, literature citations and more.