What are cookies, how do they work? - Cookies FAQ

What is a cookie?

A cookie is a small text file that is stored on a user’s web browser. The cookie is set by request by a web server to a web browser (e.g. Internet Explorer, chrome). A cookie is entirely ‘passive’ and does not contain software programmes, a virus or spyware. A cookie is composed of two parts, its name and its content or value of the cookie. Moreover, the life-time of the cookie is determined. Technically, only the web server that sent the cookie can access it again when a user returns to a website associated with that web server.

What are the advantages of cookies?

A cookie contains information linked from a web browser (the user) to a specific web server (the website).  If a web browser accesses that web server again, the web server can read from and react to that information.  Cookies ensure a user-friendly experience and support safety efforts for many online offers and services, e.g. language preferences, privacy settings, shopping baskets of online shops or relevant adverts.

What information are stored in cookies?

Cookies store data in a small text file that allow a website to recognize a browser. The web server will recognise the web browser until a cookie expires or is deleted.Cookies store useful information that improve the internet experience, e.g. store language settings in order for a user to see the website in his / her language; allow a user to remain logged-in his webmail; secure online banking; ‘remember’ the items in a shopping basket.

Are cookies spying on my computer?

No, cookies are not active programs. As a result, they cannot be spyware (that illegally intercepts data) and cannot carry a virus. They do not have access to the information on your hard drive.

Do cookies pose a security or safety risk?

No, cookies do not pose any safety or security risks. They are not ‘active’, executable, software. They do not spy on data that is stored in the computer nor can they carry a virus.

Is my privacy protected?

Usually cookies contain only a generic browser recognition or are associated with anonymous data. When cookies are set, the user is informed about it (typically in the privacy section of a website or in the terms of use or other user contract). If websites use cookies to collect personal data, data protection laws require those websites to inform users about the collection of personal data and the purpose of such collection.

Can I control cookies?

Yes, browsers offer cookie management setting tools (please see some help below). Browser settings can be set to require the user’s confirmation for each cookie that might be stored on his / her PC. You can also set the browser to accept cookies only from specific web sites (e.g. your favourite news site). Browsers can also enable users to delete specific cookies. It is even possible to set a browser to reject all cookies. Note that choosing to disable all cookies could significantly affect your web browsing experience because many Internet services rely on cookies. Here is some key information to deal with your browser’s cookies management setting tools:

Google Chrome  5.0.375.53 beta

Open your browser. Click on the icon representing “Tools” at the right of the window and choose Options. Click the “Under the Hood” tab and Click Content Settings in the Privacy section. Choose your preferred settings in the Cookies tab.

Internet Explorer version 8

Open your browser. Click on Tools at the right of the window and choose Internet Options. Click on the Privacy tab. You can choose between different levels of automatic cookies management or choose to do it manually by clicking on Advanced.

Mozilla Firefox 3.6

Open your browser. Click on Tools and choose Options. Click on the Privacy tab. In the History section you can choose between different scenarios (Remember history/ Never remember history /Use custom settings for history) and define exceptions.

Opera 10.53

Open your browser. Go to the main menu and click on Settings. Choose Preferences and click on the Advanced tab. Choose the Cookies tab and define your preferred settings.

Safari 4

Open your browser. Click on the menu icon on the far right. Choose Preferences and click on the Security tab. Define your preferred settings.

Can I disable a cookie?

Yes, some browsers will let you block just third party cookies (these are cookies placed on your browser by an entity other than the particular website’s owner- e.g., an advertising partner) or will allow the use of settings to block only cookies that do not meet your privacy preferences. However, most Websites use cookies in order to enhance a user-friendly experience and the safety of their online offers, e.g. the shopping basket of an online shop or the display of a relevant advertisement. You can choose to disable all cookies but this could significantly affect your web browsing experience. 

What is the lifespan of a cookie?

Cookies are managed by web servers. The lifespan of a cookie can vary significantly, depending on its purpose. Some cookies are used only during an online session (‘session cookies’) and are not retained once you leave a website, and some cookies are retained and used each time you visit a website (‘permanent cookies‘). However, cookies can be deleted by a user at any given time through the browser settings.

What kinds of cookies exist?There are two types of cookies: ’session cookies‘, which are automatically deleted after each session and ‘permanent cookies‘, which have a longer life-span. Both kinds of cookies can be deleted at any given time by the user. 

What are third party cookies?

Some content on a Website can be placed by a third party provider (e.g. a news box ticker, a video or an advertisement). Those third parties can also place cookies through a Website and they are called ‘third party’ cookies because they are not the Website owner. Third party providers must of course respect the applicable legislation and typically the policies of the Website owner. See also question “Can I control cookies?”

Do cookies fill up my hard disk?

No, cookies are small text files and require very little storage. 

What are flash cookies (or LSOs)?

‘Flash cookies’, referred to also as Local Shared Objects (LSOs), operate in a similar way to cookies and store preferred settings of players like Flash or Silverlight. In most cases, LSOs cannot be managed by browsers but through special manager tools:

Adobe Settings Manager for LSOs using Flash Player http://www.macromedia.com/support/documentation/en/flashplayer/help/settings_manager.html

The “Global Storage Settings panel” will allow you to choose how much disk space websites can use to store information for websites you have not visited yet (zero to unlimited). If you want to change the settings for the websites you have already visited, go to “Website Storage Settings Panel”. You can choose the level of information storage for a website or delete the website so that, if you visit it again, it will use the global settings  you have set under the “Global Storage Settings panel”.

Microsoft Settings Manager for LSOs using Silverlight

http://www.microsoft.com/GetSilverlight/resources/documentation/AppStorage.aspx

Open the Silverlight application. Click the Application Storage tab to see which Web sites are currently using application storage.

Add-on extensions have also have been created by the Firefox Web browser (Click&Clean, Objection, BetterPrivacy).