This may help you understand the functionality of commonly used icons.
These four appear at the top left area of the Zotero screen
manually create a citation
when you want to add a ciration using a numerical identifier such as a DOI or a PMID
add a previously saved file - either an individual PDF or a file saved from a database
add a note to a citation
This allows you to search for a keyword within a collection.

These icons appear at the very right of the screen and are used only for individual articles.
