Zotero is an add-on in Firefox which enables you to collect PDF files and citations.
Next to Zotero, RefWorks and Mendeley are available as citation managers. See the overview of pros and cons for each of these tools.
Zotero consists of two parts, an add-on for the Firefox browser, which you install via the Zotero website, and a web version. By registering on the website, you get your own webpage at Zotero. This page gives you access to the data that you have saved in Zotero, from any computer with internet access. The use of Zotero is free for a storage space up to 300 MB.
You can use both the add-on and the web version of Zotero on any standard UvA work space. In the add-on you can set your preferences so that new data are automatically synchronised to the web version.
There are apps available to use Zotero on mobile devices, built by third parties.
There is a plug-in for Word, which enables you to create citations and bibliographies in Word by means of data saved in Zotero. After installation, this plug-in is visble in Word under the tab Add-Ins.