Cookies are pieces of data that are stored on a person's browser. They are associated with a domain (a particular website or set of websites) and are only visible to websites and website code that is loaded form that domain. So in other words, when you go to facebook.com, that website cannot read your woopra cookie. Cookies are used to help servers remember people who come back to their site, so that they can show website data based on who is viewing the website.
The Woopra cookie is available in the browser on the
woopra tracker object:
var visitorCookie = window.woopra.cookie;
This can be useful for a number of reasons, mostly having to do with Serverside Tracking. For instance if you use Segment, and you want to do backend tracking, you will need to pass the cookie in their
integrations object in track requests. Similarly if you want to use a Woopra serverside SDK alongside your clientside tracking, you will likely need to pass the cookie to your server in order to tie serverside events to clientside events.