By visiting a website you may receive cookies from both the visited site ("owners") and from sites managed by other organizations ("third parties"). An example is the presence of "social plugins" for Facebook, Twitter, Google+ etc. These are parts of the page visited generated directly by the aforementioned sites and integrated into the page of the host site. The presence of these plugins involves the transmission of cookies to and from all sites managed by third parties. The management of information collected by "third parties" is governed by the relevant information to which reference is made. Facebook information: https://www.facebook.com/help/cookies/
Facebook (configuration): log in to your account. Privacy section.
DURATION OF COOKIES
Some cookies (session cookies) remain active only until the browser is closed or when the logout command is executed. Other cookies "survive" when the browser is closed and are also available in subsequent visits by the user. These cookies are called persistent and their duration is set by the server when they are created. In some cases a deadline is set, in other cases the duration is unlimited. Browsing on the pages of this site, you can interact with sites managed by third parties that can create or modify permanent and profiling cookies.
The user can decide whether or not to accept cookies using the settings of his browser. The setting can be defined specifically for different websites and web applications. In addition, the best browsers allow you to define different settings for cookies "owners" and those of "third parties". As an example, in Firefox, through the menu Tools-> Options -> Privacy, you can access a control panel where you can define whether or not to accept the different types of cookies and proceed with their removal.
More information on cookies: http://www.aboutcookies.org