It can be used to eliminate animal studies, restrict to a particular age group or gender, define years of publication, retrieve only articles with abstracts, limit the search to review articles or other publication types, or search only certain journals of languages. Keywords, textwords, and subject headings are used for subject searching. Keyword or textword searching means that the search will include the words found in the title or abstract of the article. The computer searches for each character in the search request and exact terms and spelling must be used for the computer to recognize a match of a citation with the request. A term may be truncated to pick up any ending but this should be done with care.
Subject headings are words chosen to standardize the terminology for a concept or topic.
Use of MeSH is important for effective searching. I know there has been research on my topic. Try the various choices. A technique for determining the correct MeSH is to search your term as a keyword. Examine the MeSH in citations that address your topic.