How is the GenBank used in typical biological research?
Go to Google Scholar. Enter "Genbank" into the search field and press return. Limit the results to 2013 and later (left side of the results).  Skip the few entries that say only "GenBank." Browse through the pages and pages of search results to get a feel for the many ways that GenBank is used in scientific research. It's used from everything for phylogenetic analysis (relationships among organisms) to determining protein structure and so much more.