Definition
Small caps
Small caps are capital letters drawn at roughly the height of a lowercase x, used for acronyms and chapter openings. True small caps are cut by the type designer; fake ones are shrunk capitals.
The difference is visible and matters in print. A real small cap is redrawn with thicker strokes so it holds its colour beside full-size letters; software that simply scales a capital produces strokes too thin, and the word looks faded on the page. The common book uses are the first few words of a chapter after a drop cap, and acronyms in body text, which set in full capitals would shout.
Related tools & guides
See it handled in your own manuscript
Ceeryo sets your .docx as a book — justified and hyphenated text with widows, orphans and rivers controlled, drop caps, running heads — and shows you every spread before you pay anything.