Words evolve, change and exploring those historical background allows us to "explode" a single concept into many ideas.
Making connections that may not have been apparent, unveiling the "unknown" and confronting confirmation bias.
Defining complex words allows the writer to clarify, provide accuracy and authority. Look for synonyms or subject headings and keywords.
Different disciplines apply words different ways. A psychologist will treat the term "climate change" as it relates to our mental health, while a chemist will treat the term "climate change" by analyzing the chemical changes in the environment. Each important, but very different methods of study.
An index is a list organized by subject, authors or keywords, often in alphabetic order, with a page number or other linked method to locate further information about that item.
Western University Library. Aug. 26, 2016 (4:21)