Imagine you are doing research for this assignment: Research and discuss how social media affected voter engagement in the 2016 election.
The words AND/OR/NOT (sometimes called Boolean) can be used to group sets of search terms together in a meaningful way; which will improve the quality of your search results because you are customizing the results to suit your specific needs/topic.
Each database/resource will have a different vibe or look, but here are some tips for enhancing your searching to get better results, faster.