Is there a lexicon for the icons on a Mac? I want to know about the "lightning bolt" symbol and wondering if there is a lexicon or summary of the meanings of all these icons.
Apple Publishes a style guide that covers official naming:


https://itunes.apple.com/WebObjects/MZStore.woa/wa/viewBook?id=1161855204


Older versions were PDF so you can find them online, but it’s now an electronic publication.