Databases are compilations of references (sometimes with a link to the full text), articles, reports, and conference proceedings. Most often, keyword indexing allows you to run searches by topic.

Journal aggregators provide full-text access to the articles and provide for reassembling the Table of Contents of issues or compiling information into booklets. You can run a search for a word from the full text.

Libraries usually have a list of all the journals to which they have subscribed, in alphabetical order. This allows users to access journals irrespective of the aggregator to which they belong.

For users, content (e-journals and e-books) aggregation is both qualitatively and quantitatively advantageous: it provides for a unique entry point to access the extended corpora of several producers.

Some publishers impose an embargo of several months or even several years to protect the print version. This can penalise researchers.

The same article can be published in a journal in an aggregator and be deposited in an open archive if the author has chosen to do so (and if allowed by the publishing contract).

The preprint version of the article can also be deposited before publication.

Online news cannot be accessed via the scholarly journal aggregators described in this guide. Several news database producers exist. They are known as news aggregators. The best known are Factiva, Europresse and Lexis Nexis.

There are also some free services such as Google News. However, you can only locate the information for free. A fee will be charged for accessing the full text.