Google Scholar does several things.
First, it indexes many free materials on the internet that you can use.
Second, and just as important, Google Scholar provides a very handy
citation index. A citation index shows where and when an article has been cited by other authors. Therefore, if you are interested in a book or article from 1996, you can find other related materials published later. This is a very powerful tool.
Example: Someone finds the following book interesting.

Search the subject in Google Scholar:
Art, Roman Egyptian influences. Google Scholar will show several types of results: some that are
free, others that are
pay, and others that are available through our electronic resources through the
College of Staten Island.
Item available through Staten Island/CUNY The first item:
Brother-Sister Marriage in Roman Egypt is an article published in the journal
Comparative Studies in Society and History. To discover if this article is available through the Staten Island/CUNY electronic resources, click on "Journals" in the catalog and search the
journal title (or copy & paste it).
Search the journal title.
This shows that the journal is available to us electronically, and the date of the article is also available (the article was published in 1980, while the coverage of the journal is from 1958-2000).
Citations Click on the citations to find later articles. Several materials are full text.
Search engines have not yet standardized their search methods, so each has its own peculiarities. Please experiment with different methods, since it is impossible to predict which ones will and will not work. As always, if you need assistance,
ask a librarian.