Why should you use the library databases and not Google to find articles?
Most of the time, scholarly publications are not available to the general public, nor are they available for free on the internet. Individuals or organizations (such as a library) subscribe to these publications. Because subscriptions are expensive, many choose to access this content through libraries.
Often, content from scholarly journals is indexed in databases that the library subscribes to. The content is on the web, but it is not accessible unless you are affiliated with the institution that is subscribing. It isn’t the same thing as just finding a website through a regular Google search. Sometimes the full text of the article is available through the database; other times it is only a citation to the article and you will need to find the print version of the article in the library or order the article through interlibrary loan if we don’t subscribe to it.
So, basically what I'm saying is that the only way you can access this scholarly information for free is by using the library databases!