What does Google Scholar have? 

Google Scholar indexes

• journal articles
• conference papers
• theses and dissertations
• academic books (especially collections of chapters by different authors)
• pre-prints (openly available early versions of articles usually in subject repositories) 
• abstracts
• technical reports
• patents
• More details: https://scholar.google.com/intl/en-US/scholar/help.html#coverage

What's great about Google Scholar

• Easy to use
• Can be linked to duPont library and other libraries 
• You can use the "cited by" feature to find more relevant material
• Like library databases, one can link to a reference manager and/or generate a citation

What isn't great about Google Scholar

• Lacks subject and disciplinary focus (library databases are often specialized)
• Hard if not impossible to limit or filter your search
• Often leads to publisher or vendor websites which require you to pay for an article
• Requires customization to work with library resources