Google Scholar uses the Google search engine to search for scholarly materials, such as research papers, preprints, theses, books, and reports, coming from a variety of academic publishers, professional societies, repositories and universities sites.
Use the Basic search to perform simple word searches like in "regular" Google.
Use the Advanced Search to use options like phrase searching, or to specify the author name, publication name, subject area, etc.
More information about Google Scholar is available at here.