The language used in searching is core to ones success in finding information on a topic. There are two main genres of search language - subject headings and keywords. Use both for the most comprehensive results. Check with a Reference Librarian for assistance with search terms.
1.) A subject heading is an assigned word or phrase used in library catalogs and some databases to uniformly describe a concept. Searching using a standardized word or phrase, instead of keywords, means you do not need to worry about synonyms and spelling variations. For example, the following are headings used in the library catalog and often in article databases to label all works related to the topics. They are part of a "controlled vocabulary" which identifies topic and subject matter. Click on any these headings to find library books and media, etc. Also try copy and pasting them in a database search
2.) Keyword searching is how most of us approach searching websites and databases. Also called "natural language, this is searching words or concepts which we expect to find in the title or content of sites and articles. They might be popular terms or those coined by others (authors, journalists, historians) to describe the topic. For example, the Great Migration, the focus of this guide, has also been described using the concepts Negro exodus or Black migration, Negro migrations, etc. But, keep in mind that the phrase "great migrations" can also refer to mass movements of other people or to movements of animal groups. When searching for articles written in the past, one needs to use the terminology, language, phrases, etc which were common at the time and used by journalists and reporters.