Zotero is a citation manager
Citation managers, like Mendeley, EndNote, and Zotero, help you to gather all your sources and citations into your own mini-database. They communicate with your word processor to help you insert in-text citations, and create bibliographies in a specific citation style, such as MLA, APA, and others.
Zotero runs on your computer but syncs and stores references online
"If you choose to create an account and sync your data, you’ll also have access to your web library on zotero.org. However, while the web library allows you to view and edit your data and access synced files, for full functionality you’ll want to install Zotero on each synced computer." - Zotero website
ZoteroBib is a simpler Zotero option
If you’re not able to, or would rather not, install software and just need to create quick bibliographies, there is a web option called ZoteroBib.
Not sure if Zotero is for you? Compare it to other citation managers
Not sure if Zotero is for you? Take a look at our comparison charts. They feature different citation management systems: EndNote, Mendeley, Paperpile and Zotero.