Zotero (pronounced "zoh-TAIR-oh") is an application that collects, manages, and cites research sources. It's easy to use, connects with your web browser to download sources, and best of all it's free.
Zotero allows you to attach PDFs, notes, and images to your citations, organize them into collections for different projects, and create bibliographies.
To use Zotero, you'll need to install two things:
Both of these are available from the Zotero download page.
Download and install Zotero from the Zotero website.
(There's a different version for each operating system: Windows, Mac or Linux.)
Connectors allow your web browser to save citations to your Zotero library.
The Zotero downloads page should automatically detect what browser you're using and give you a link.
Each browser has its own version of the Zotero connector, so if you use Chrome, Edge, Firefox, and Safari you'll need to install all four.