What is a cookie?
A cookie is a small file, typically of letters and numbers, downloaded on to a device when the user accesses certain websites. Cookies allow a website to recognise a user’s device. Cookies can expire at the end of a browser session (from when a user opens the browser window to when they exit the browser) or they can be stored for longer.
When are cookies created?
Writing data to a cookie is usually done when a new webpage is loaded - for example after a 'submit' button is pressed the data handling page would be responsible for storing the values in a cookie. If the user has elected to disable cookies then the write operation will fail, and subsequent sites which rely on the cookie will either have to take a default action, or prompt the user to re-enter the information that would have been stored in the cookie.
What are session cookies?
Session cookies allow websites to link the actions of a user during a browser session. They may be used for a variety of purposes such as remembering what a user has put in their shopping basket as they browse around a site. They could also be used for security when a user is accessing internet banking or to facilitate use of web mail. These session cookies expire after a browser session so would not be stored longer term. For this reason session cookies may sometimes be considered less privacy intrusive than persistent cookies.
What are persistent cookies?
Persistent cookies are stored on a users’ device in between browser sessions which allows the preferences or actions of the user across a site (or in some cases across different websites) to be remembered. Persistent cookies may be used for a variety of purposes including remembering users’ preferences and choices when using a site or to target advertising.
What are third party cookies?
Whether a cookie is ‘first’ or ‘third’ party refers to the website or domain placing the cookie. First party cookies in basic terms are cookies set by a website visited by the user - the website displayed in the URL window. Third party cookies are cookies that are set by a domain other than the one being visited by the user. If a user visits a website and a separate company sets a cookie through that website this would be a third party cookie.