In some countries or areas of the world, you can find abstracts of journal articles included within a search result of a library catalog. This is generally not the case within the U.S. however. Also, library catalogs generally don't include the full text of the item described in the library record. They will give you information on the availability of the item, as well as where it is located.
Please note that easy access is provided to Harvard University's catalog in both its interfaces on the right side of this page. If you are unsure as to which version is better for your research, please see the videos listed on this page. Please also see the video tutorials prepared by the Harvard Law Library, which show you how to find journals, books, and newspapers within the Hollis Classic catalog, and via the Harvard Libraries' E-Resources page.