Zotero can be used solely as a web-based library but more functionalities are available with the downloadable desktop tool (Mac, Windows, and Linux). You can use both the web library and desktop library as they'll sync up.
The Zotero Connector is a browser plug-in (Firefox, Chrome, Edge, or Safari) that allows you to save whatever you come across online into your web/desktop library.
ZoteroBib is a free web-based citation tool that generates citations from URL metadata, and saves what you enter to create a bibliography. It's free!
Zotero's basic File Storage plan (300mb of storage) is free, but there is a charge for more storage:
Group libraries can be created through zotero.org, and file storage for shared libraries will draw from the storage account of the group owner.
As open-source software, Zotero allows its users to create fixes and tools to improve the usability and function of the citation manager.
Citation management tools all come preset with many of the major styles (APA, MLA, Chicago, AMA, etc.) but Zotero can also import new CSL files to format your citations in the style of whatever journal or publisher with whom you might be working.
The process to do so is as follows:
You can connect Zotero to the Library's OpenURL resolver so that citations can be searched for in the Library's collections through the Library Lookup tool.
Go to Preferences in Zotero Desktop, and under the Advanced tab, look for and select the resolver labeled "Stevens Institute of Technology" or enter the URL listed there (see image).